for an Invention of APPARATUS FOR INTERMITTING AUDIBLE SIGNALS
Year: 1881

page_text: LETTERS PATENT to Frederick William Durham, of Station Road, New
"IMPROVEMENTS IN
Barnet, in the County of Herts, for an Invention of
APPARATUS FOR INTERMITTING AUDIBLE SIGNALS."
PROVISIONAL SPECIFICATION left by the said Frederick William Durham
at the Office of the Commissioners of Patents on the 29th September
1881.
FREDERICK WILLIAM DURHAM, of Station Road, New Barnet, in the County of
Herts. "IMPROVEMENTS IN APPARATUS FOR INTERMITTING AUDIBLE SIGNALS."
On board steam vessels it is usual in fog or obscure weather to sound inter-
mittently a steam whistle or horn as an audible signal, and the intermissions are
ordinarily effected by hand applied at stated intervals to the cock or valve of the
instrument. My Invention relates to apparatus for automatically effecting such
intermissions, the apparatus being capable of adjustment to suit various intervals
of intermission and being such as not to interfere with the working of the signal
by hand when required. For this purpose I attach to the steam pipe leading to
the whistle or horn a small cylinder fitted with a piston or plunger which is
connected to the cock or valve of the sounding instrument, and which is also
connected to a remontoir spring or weight that drives clockwork. This clockwork
is provided with a flyer or balance that can be adjusted so as to regulate the speed
of the clockwork as may be desired, and it works by suitable gear a slide or valve
governing the communication from the steam pipe to the small cylinder. The
clockwork being started goes on for a time, and when its gear has moved a certain
amount it opens the admission port to the small cylinder; its piston or plunger
being thus subjected to the steam pressure moves, opening the cock or valve of the
signal, which thereupon sounds. This movement of the piston or plunger also
CD 033

page_text: strains the remontoir spring or raises the remontoir weight sufficiently to drive the
clockwork during the next interval. The clockwork still going on shifts the slide or
valve of the small cylinder so as to relieve from pressure its piston or plunger, which
is thereupon caused to make its back stroke by a weight or spring that at the same
time closes the cock or valve of the signal. The clockwork still going on after the
interval determined by the speed to which the flyer or balance is adjusted repeats
the action, and so on continuously. The connection from the piston or plunger to
the cock or valve of the signal is made by a flexible band or chain, or by a link
slotted, so that the cock or valve can be opened by hand while the piston or plunger
is inert.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick William Durham in the Great Seal Patent Office on the
24th March 1882.
:
FREDERICK WILLIAM DURHAM, of Station Road, New Barnet, in the County of
Herts. "IMPROVEMENTS IN APPARATUS FOR INTERMITTING AUDIBLE SIGNALS."
On board steam vessels it is usual in fog or obscure weather to sound inter-
mittently a steam whistle or horn as an audible signal, and the intermissions are
ordinarily effected by hand applied at stated intervals to the cock or valve of the
instrument. My Invention relates to apparatus for automatically effecting such
intermissions, the apparatus being capable of adjustment to suit various intervals
of intermission, and being such as not to interfere with the working of the signal
by hand when required. For this purpose I attach to the steam pipe leading to
the whistle or horn a small cylinder fitted with a piston or plunger, which is
connected to the cock or valve of the sounding instrument, and which is also
connected to a remontoir spring or weight that drives clockwork. This clockwork
is provided with a flyer or balance that can be adjusted so as to regulate the speed
of the clock work as may be desired, and it works by suitable gear a slide or valve
governing the communication from the steam pipe to the small cylinder. The
clockwork being started goes on for a time, and when its gear has moved a certain
amount it opens the admission port to the small cylinder; its piston or plunger
being thus subjected to the steam pressure moves, opening the cock or valve of the
signal, which thereupon sounds. This movement of the piston or plunger also
strains the remontoir spring or raises the remontoir weight sufficiently to drive the
clockwork during the next interval. The clockwork still going on shifts the slide
or valve of the small cylinder so as to relieve from pressure its piston or plunger,
which is thereupon caused to make its backstroke by a weight or spring that at
the same time closes the cock or valve of the signal. The clockwork still going
on after the interval determined by the speed to which the flyer or balance is
adjusted repeats the action, and so on continuously. The connection from the
piston or plunger to the cock or valve of the signal is made by a flexible band or
chain, or by a link slotted so that the cock or valve can be opened by hand while
the piston or plunger is inert.
The accompanying Drawing is a vertical section of apparatus according to my
Invention. A is a small steam cylinder fitted with piston B, the rod of which is
connected by a link C to the cock or valve of a steam whistle or other audible
signal, so that when the piston B makes its upstroke this cock or valve is opened
and the signal is caused to sound and continues sounding until the piston B
descends; D is a barrel containing a volute spring like that of a clock or watch,
one end of the spring being attached to the axis E and the other end to the
circumference of the barrel D in the usual way. On the axis E is a ratchet wheel
with the teeth of which engages a spring pawl F mounted on a lever G that is
linked to an arm H projecting from the rod of the piston B. Another pawl K
prevents the axis E from turning backwards. The barrel D is connected by
multiplying clockwork gear to a flyer L, the wings of which can be adjusted so as
to meet more or less resistance of air as they revolve, thus controlling as desired
the speed of the clockwork. On the edge of the barrel D are formed a number of
projecting cam teeth or wipers M with spaces between them. On these wipers is
pressed by a spring O a roller n, which is mounted on one end of a lever N
connected at its other end to the rod of the steam slide P. The apparatus acts in
the following manner:-The supply Q to the case of the slide P being connected

page_text: to the steam pipe of the signal, and the spring in the barrel D being wound up in
the first instance, this spring sets the clockwork in motion at a speed determined
by the resistance of the flyer L. When after a certain time the wiper M moves
away from under the roller n so that this roller drops into the space between this
wiper and the next, the slide P is by this movement of the lever N raised,
admitting steam under the piston B and allowing steam from above it to escape by
the exhaust passage R. The piston B then makes its upstroke, opening the cock
or valve and causing the signal to sound. At the same time this upstroke of the
piston raising the lever G turns the axis E of the spring partly round and so
winds up the spring to the extent to which it had unwound itself. While the
roller remains in the notch the signal continues to sound, but when by the
advance of the incline of the next of the wipers M the roller n is raised, then the
slide P being caused to descend, the steam pressure now acts on the upper side of
the piston B, causing it to descend and to close the cock or valve of the signal,
which remains closed till the next notch presents itself for the descent of the
roller n, whereupon the action is repeated. Obviously by suitably proportioning
the length of each wiper M to that of the space between it and the next, and
adjusting the resistance of the flyer L to the strength of the spring in D, the
interval between the successive soundings of the signal and the period during which
in each case it continues to sound can be regulated as desired. For the purpose of
throwing the apparatus out of action, a hook S can by moving an external
handle be made to engage a pin on one of the gear wheels and so stop the
clockwork.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim,—
In apparatus for intermitting audible signals, working the cock or valve of the
signal by the movement of a piston in a cylinder subject to the pressure of
the working fluid, the admission and emission of which are timed by clockwork
wound up by each stroke of the piston, substantially as herein described.
In witness whereof, I, the said Frederick William Durham, have hereunto
set my hand and seal, this Twenty-second day of March, in the year of
our Lord One thousand eight hundred and eighty two.
FREDERICK WILLIAM DURHAM, (L.S.)