Improvements in Screens for Ships' Side Lights.
Year: 1891

page_text: Date of Application, 26th Mar., 1891
Complete Specification Left, 2nd Sept., 1891-Accepted, 17th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in Screens for Ships' Side Lights.
I, ALFRED JOHN LOFTUS, Phrá Nidesa Ialahdi K.C.C.S. of Wat Chang,
Bangkok, Siam, Captain and Hydrographer in His Siamese Majesty's Navy, do
hereby declare the nature of this invention to be as follows:-
My invention relates to the construction of the screens used in connection with
ships side lights and is intended to afford better protection to the lamps and to
increase the brilliancy of the light emitted and secure other collateral advantages.
My said screens are similar in most respects to those usually employed but are
provided with internal reflectors whereby rays of light which would otherwise be
lost are reflected into a useful direction.
The bottom plank or floor of the screen I narrow off from a point near the lamp
towards the fore end of it, forming it in a curve offering least resistance to the
impinging water when a sea is shipped and so that light from the lamp may be
better seen by small vessels low in the water ahead of the ship and I also provide
one or a series of water holes to facilitate the escape of the water and access
of air.
Within the screen and on the side of it next the ship I attach one or more
reflectors in such position that the rays of light proceeding from the lamp, or
some of them, which would otherwise strike the dull surface of the screen and
be lost are reflected into a direction in which they are useful-I may also fix
small auxiliary reflectors within the lamp.
I prefer to attach the lamp to the screen by means of a stud projecting from
the lamp which passes through the screen behind which it is secured by a bolt or
otherwise.
The reflector or reflectors within the screen may be made of silvered glass,
metal, enamel or other bright or reflecting material and may be made to completely
cover the interior of that side of the screen next the ship or may be placed at
intervals and at varying angles, preferably the reflectors are not placed in
absolute contact with the interior surface of the screen but are mounted at a short
distance from it.
Dated the 26th day of March 1891.
NEWNHAM BROWNE,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Screens for Ships' Side Lights.
I, ALFRED JOHN LOFTUS, Phrá Nidesa Ialahdi, K.C.C.S. of Wat Chang
Bangkok, Siam, Captain and Hydrographer in His Siamese Majesty's Navy
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 :-
My invention relates to the construction of the screens used in connection with
ships' side lights, and is intended to afford better protection to the lamps, and to
increase the brilliancy of the light emitted, and secure other collateral advantages.
My said screens are similar in most respects to those usually employed, but are
provided with internal reflectors whereby rays of light which would otherwise be
lost are reflected into a direction in which they are useful.
Within the screen and on the side of it next the ship I attach one or more
[Price 8d.1

page_text: reflectors or equivalents therefor in such position that the rays of light from the
lamp or some of them, which would otherwise strike the dull surface of the screen
and be lost, are reflected or bent into a direction in which they are useful, I may
also fix small auxiliary reflectors within the lantern.
The reflector, or reflectors, within the screen may conveniently be made of
silvered glass, metal, enamel or other bright or reflecting material, and may be
made to completely cover the interior of that side of the screen next the ship and
adjacent parts, or may be placed at intervals and at varying angles, and preferably
the reflectors are not placed in absolute contact with the interior surface of the
screen but are mounted at a short distance from it.
The reflector, or reflectors, may be replaced by any optical equivalent therefor,
such as refracting prisms, acting by internal reflection, as hereinafter described.
In the accompanying drawings I have shown the arrangements which up to the
present I have found most advantageous but my invention is not limited to the
number, size or position of the reflectors, or prisms represented which, obviously
may be varied indefinitely.
In the drawings
Fig. 1 is a plan of one of my improved screens with the lamp fixed therein.
Fig. 2, is an elevation of the same without the lamp, and
Fig. 3, is a back, or outside elevation of the same, the right hand lower corner
being shown broken away to enable the parts behind it to be seen.
Fig. 4, is a plan, and Fig. 5, an elevation of a similar screen fitted with prisms,
instead of reflectors, and
Fig. 6, shows how the prisms may be inclined so as to increase the vertical
range of the reflected or refracted rays.
Fig. 7, shows the screens fixed to a ship's side, and the direction in which the
bent rays are emitted. The direct rays from the lamp are not shown as their
course is obvious and their insertion would tend rather to confuse the drawings by
a multiplicity of lines.
Fig. 8, is a plan, Fig. 9, an elevation and Fig. 10, a transverse section of a
screen in which nearly the whole length of the screen is faced with a curved sheet
of metal or the like.
I will first describe the screen represented in Figs. 1, 2, and 3, in which A
is a board forming the side, or back, of the screen. B is the board forming
the bottom thereof and which is narrowed off towards the fore-end of it so as
to offer less resistance to the impinging water when a sea is shipped, and so that
the light from the lamp may be better seen by small vessels low in the water
ahead of the ship; C is the board forming the end. D is the lamp from which
projects a stout bolt d, by means of which the lamp is fixed in the screen.
bolt.d passes through a hole e, preferably bushed and protected by a metal plate
on each side, the outer plate carrying a cross bolt f which may be shot into a hole
through the bolt d whereby the lamp is securely fixed in the screen. The bolt fis
prevented from being jarred out of place by the usual arrangement of the slot in
the bolt-cover through which the handle of the bolt works.
The
G, is an opening through the board A, on the level of the upper side of the
board B, which serves to facilitate the escape of water from the screen.
H is a
similar but larger opening intended principally to admit air behind and under the
lamp, and also for the escape of water; J, is an opening through the end C, of the
screen for the admission of air. K is a reflector fixed in the screen so as to receive
and reflect some of the rays of light as shewn by the dotted lines which rays would
otherwise strike the side or back A of the screen and be lost. L, is another
reflector for the like purpose and arranged to receive others of such
which are
rays
not reflected by K. The reflector L is preferably fixed slightly obliquely to the
side of the screen so as to receive and reflect more light than it would if placed
parallel to it; m and n, are two small reflectors placed within the lamp for the
purpose of utilising those of the rays which neither pass directly out through
the lens nor are reflected by the reflector P. Q, is the flame of the lamp.

page_text: In Figs. 4, 5 and 6 the same letters of reference indicate the same parts except
those referring to the reflectors K and L, which are replaced by equivalent
prisms R, R, which are arranged so that the rays which pass through one may
escape contact with the next and so that the rays which just escape contact with
the first may enter the second and so on as shewn in Fig. 4. In Fig. 6 the prisms
instead of being placed vertically are inclined, an arrangement I sometimes adopt.
Figs. 8, 9 and 10 represent a screen in which instead of several reflectors one long
reflector S is used reaching almost from the lamp to the front end of the screen
and which may either be plane or curved as shewn in transverse section in
Fig. 10 such reflector may conveniently be made of polished or enamelled sheet
metal.
I have shown the reflectors with plane surfaces in Figs. 1 to 6, but it is obvious
that some amount of curvature may be given to the reflecting surfaces therein
illustrated, if desired, and I make no claim to the precise forms of any of the
reflecting surfaces.
Lamps mounted in my improved screens give an exceedingly good light ahead
that being the direction in which the brightest light is most needed.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. Constructing screens for ships' side lights substantially in the manner and for
the purpose described and set forth.
2. Constructing screens for ships' side lights with a reflector or reflectors or
equivalent prisms or both of them arranged to utilize light which would otherwise
be wasted substantially as hereinbefore described and set forth.
3. Constructing screens for ships' side lights with a lining of bright or reflecting
material substantially as described and set forth.
Dated this 2nd day of September 1891.
NEWNHAM DROWNE,
Agent for the Applicant.