Improvements in Flash Signalling Apparatus.
Year: 1888

page_text: Date of Application, 5th Dec., 1888
Complete Specification Left, 5th Sept., 1889-Accepted, 5th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Flash Signalling Apparatus.
I NESBIT WILLOUGHBY WALLACE, of St. John's, Bishopstoke in the County of
Hants, Lieut. Colonel retired H.M.S., do hereby declare the nature of this Invention
(a communication to me from abroad by Percy Scott, Commander R.N. at present
serving on board H.M. Ship Edinburgh, Malta) to be as follows:-
This Invention relates to flash signalling apparatus particularly designed for ships'
masthead, and other lights used for signalling at sea; and the invention has for its
principal object to provide a means of rapidly eclipsing or exposing the light as may
be required and such as to afford an "all round" exposure or permit of the light
being seen from all directions at once, the said means of eclipsing the light being
workable either from a distance by electrical agency or otherwise as may be required.
The Invention consists in such a construction of eclipse shutter that motion of the
same through but a very small distance will be sufficient to completely expose, or
completely obscure, the light through the entire circle of the horizon. This result
may be accomplished in various ways, as hereafter described..
According to one arrangement, the shutter comprises a fixed and movable or two
oppositely movable concentric cylinders surrounding the source of light, the said
cylinders fitting closely the one around the other and being provided with apertures
which, by a very small motion of the cylinder or cylinders, may be made to coincide
and give a practically all round emission of the light, the cylinders, when their
apertures do not coincide, each mutually closing the apertures of the other so as
to totally eclipse, the light. The apertures may be so arranged that the opening
and closing thereof is effected by a rotary motion of one or both shutters about a
vertical axis and through a very sunall arc and such rotary motion may be imparted
in the one direction by spring power and in the other through the agency of an
electro-magnet energised by a current controlled from a distance. Or, the motion
may be a sliding one in the vertical direction in which case the shutters may be
of polygonal, instead of cylindrical, form and the motion, as in the former case,
may be imparted manually or mechanically instead of electrically. In this case also,
a single shutter without apertures might be used and its sliding motion may be co-
extensive with the height of the shutter.
According to another arrangement, the shutter is constructed of louvres arranged
in a circle, each louvre being capable of partial rotation upon its own vertical axis
and the whole of their axes being geared with, and operated from, a central spindle
whereby the whole of the louvres may be simultaneously turned from a position in
which their edges mutually overlap each other to, or through, a position in which
their edges are presented radially to the light enclosed within them. In the first
mentioned position the light is completely obscured and in the position last mentioned
the louvres present little or no obstruction to the radiation of the light in all directions.
The central spindle from which the louvres are operated, carries a polarized armature
influenced by electro-magnets energised by currents controlled from a distance, or
they may be operated mechanically or. by hand, as in the former case.
Any kind of light may be used whether electric, oil, lamp, or candle.
Dated this 5th Ja
L. 1000

page_text: COMPLETE SPECIFICATION.
Improvements in Flash Signalling Apparatus.
I, NESBIT WILLOUGHBY WALLACE, of St. John's, Bishopstoke, in the County of
Hants, Lieut-Colonel retired H.M.S. do hereby declare the nature of this invention
(a communication to me from abroad by Percy Scott, Commander R.N., at present
serving on board H.M. Ship Edinburgh, Malta,) and in what manner the same is
to be performed, to be particularly described and ascertained in and by the following
statement:
This Invention relates to flash signalling apparatus particularly designed for
ships masthead (and other) lights used for signalling at sea; and the invention
has for its principal object to provide a means of rapidly eclipsing and exposing the
light, the exposure being an "all round one permitting the radiation of the light in
all directions at once, the eclipsing device being workable from a distance either by
electrical or other agency.
,,
The Invention consists in such a construction of eclipse shutter that motion of the
saine through but a very small distance will be sufficient to completely expose or
completely obscure, the light through the entire circle of the horizon. This result
may be accomplished in various ways, as hereafter described with reference to the
accompanying drawings forming part of this specification wherein figure 1 represents
a vertical section of one arrangement of eclipse shutter for a masthead light.
Figure 2 is a horizontal cross section of same on line 2-2 figure 1. Figure 3 is a
vertical section, and figure 4 a horizontal cross-section, of another arrangement of
eclipse shutter (closed). Figure 5 is a half cross-section, drawn to a larger scale
and shewing the same shutter open. The same letters of reference indicate like
parts in all the figures.
According to the arrangement illustrated in figures 1 and 2, the shutter comprises
concentric cylinders A B, the one A fixed and the other B movable about its axis or
both may be oppositely movable about their common axis. The cylinders surround
the source of light (which in the example shewn is a glow lamp) the said cylinders
being provided with vertical slits or apertures ab which by a rotary motion of the
one cylinder with regard to the other through a small are, may be made to coincide
and so give a practically all round emission of the light. The slits are at equal
distances apart slightly greater than the width of the slits so that when apertures
in the one cylinder coincide with the intervening bars of the other cylinder, the
cylinders will each mutually close the apertures of the other so as to entirely prevent
the emission of the light.
In the example illustrated, the outer cylinder A is stationary and the inner one B
is carried by a central vertical axis C below and revolves about an axis c above by
which it is kept truly concentric with the outer cylinder A within which it fits with-
out frictional contact at the periphery but with sufficient accuracy to ensure the
obscuration of the light when the shutter is closed. To the axis C is attached the
soft iron armature e of an electro magnet E which is energised by a current controlled
from any convenient distant point, rotary motion being imparted to the cylindrical
shutter B through an arc corresponding to the width of one of the apertures a bin
the one direction by the electro magnet and in the other direction by an antagonistic
spring d.
Instead of the spring a polarized armature between a pair of electro-magnets with
reversals of current may be used as in figures 3, 4, and 5. Instead of the slits a b
being vertical and the motion of the cylinder B rotary, the slits might be horizontal
and the cylinder have a vertically sliding motion, the weight of the cylinder being
counter-balanced and the transmission of motion by the electro-magnetic contrivances
suitably modified. Or in either case, instead of operating the shutter electro-
magnetically it may be operated by manual power through a line or other mechanical
contrivance as will be readily understood.
In the arrangement illustrated in figures 3, 4, 5, the shutter is constructed of

page_text: louvres F arranged in a circle around the light, each louvre being capable of partial
rotation upon its own vertical axis ff' and the whole of their axes fbeing operated
from a wheel G on a central spindle g, each spindle having a crank arm engaged
in a radial notch h¹ in the said wheel whereby the whole of the louvres may be
simultaneously turned from a tangential position in which their side edges mutually
overlap each other, as shewn in figure 4, to a radial position in which their edges
only are presented to the light, as in figure 5. In the first mentioned position the
light is completely obscured and in the position last mentioned the louvres present
little or no obstruction to the radiation of the light in all directions. The central
spindle g from which the louvres are operated carries a polarized armature e influenced
by electro-magnets E energised by currents controlled and reversed from any con-
venient distant point or the spindle may be operated by a soft iron armature acting
against the force of a spring as in the previous case or the louvres may be operated
mechanically or by hand, as in the former case. These louvres are preferably enclosed
in a cylindrical glass casing I.
Any kind of light may be used whether electric, oil, lamp, or candle.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is;
1. The herein described eclipse shutter for flash signalling apparatus, consisting
of concentric vertically-slotted cylinders enclosing the light and adapted to exhibit or
obscure the light by the coincidence or the mutual obstruction of their apertures
brought about by a slight rotary motion of the one cylinder, as specified.
2. The combination of the herein described eclipse shutter consisting of concentric
vertically-slotted cylinders operating as described, with electro-magnetic apparatus
for imparting a partial rotation to one of the cylinders, substantially as specified.
3. The herein described eclipse shutter for flash signalling apparatus consisting of
concentric horizontally-slotted vertical cylinders adapted to exhibit or .obscure the
light by a slight vertical sliding motion of one of the cylinders, substantially as
specified.
4. The herein described eclipse shutter for flash signalling apparatus consisting of
an annular series of vertically pivoted louvres, adapted to overlap one another and
form a practically continuous enclosure for the light or to be moved each from the
tangential to a radial position in which their edges only are presented to the light.
5. The combination with the herein-described annular series of vertically pivoted.
louvres, of the crank arms and notched wheel for operating them as described, and of
a polarized or soft iron armature influenced by electro-magnets, as specified.
Dated this 5th day of September 1889.
Dated is way of September 1
N. W. WALLACE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.