Improvements in Railway Signal Lamps and other Lamps, and in Appliances to be Used with Railway Signal Lamps and other Lamps.
Year: 1885

page_text: Improvements in Railway Signal Lamps and other Lamps, and
in Appliances to be Used with Railway Signal Lamps and
other Lamps.
I SAMUEL TELFORD DUTTON of N° 1 Saint George's Square in the City of
Worcester Civil Engineer do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN RAILWAY SIGNAL LAMPS AND OTHER LAMPS AND IN
APPLIANCES TO BE USED WITH RAILWAY SIGNAL LAMPS AND OTHER LAMPS " to be
as follows:-
My improvements have reference principally to railway signal lamps and
appliances to be used with lamps made according to my invention but my said.
invention is applicable wholly or in part to lamps other than railway signal lamps.
I will describe my invention in connection with a railway signal lamp. I make
the lens and the reflector of the lamp in the following manner. The whole of the
back of the lens is flat and the central portion of the front of the lens is convex
the central part of the lens having the figure of an ordinary plano-convex lens.
Around the central part of the lens is a series of concentric zones the front faces of
which are convex the convexity of the zones diminishing progressively as the said
zones are situated more and more distant from the centre of the lens. Thus the
radius of curvature of the zone immediately surrounding the central part of the
lens is somewhat longer than the radius of the front of the said central part of
the lens; the radius of the second zone is somewhat longer than that of the first
zone and so on the radii of the zones increasing in length and the radial point in
distance from the plane side of the lens as the zones are more distant from the
centre of the lens. By this construction of lens the central portion refracts the rays
of light incident upon it into a cylindrical beam of light while the successive zones
refract the light incident upon them more and more outside the beam of the
central portion. The result of these refractions is to produce a beam of light
having a conical figure and visible within an area gradually widening from the
lamp.
At the back of the flame is a convex reflector and surrounding the top and
sides of the flame is a reflector of a nearly conical figure the curvatures of the
said reflectors being such that the light incident upon and reflected by them con-
spires with the refracted light to produce the conical beam of light hereinbefore
referred to

page_text: Instead of the outline of the lens being circular it may be oblong its greatest
length being horizontal as the object is to produce a beam of light visible within
an extensive horizontal range but of limited range vertically.
The lamp may either burn oil or gas. When gas is used the oil reservoir and
burner are removeable. The lamp is provided with a bonnet or deffector for
directing a current of air to the flame. This deflector moves vertically. When the
lamp is removed from its case this deflector takes its lowest position resting on
the top of the reservoir and thus protecting the flame from the wind but when the
lamp is put in its place in the lamp case the bottom edge of the deflector coming
in contact with the false bottom of the case its further descent is prevented and as
the reservoir is depressed into its seat the air passages by which air is supplied to
the flame are opened.
To fit the lamp for burning gas a gas pipe furnished with any desired jet or
burner is fixed on the bottom of the lamp case the said pipe turning upon a joint
and being capable when not required to be used of lying flat on the bottom of the
case. For use it is raised into a vertical position in which position its jet or burner
occupies the position of the jet of the oil lamp inside the reflector.
The vitiated air and products of combustion pass upwards through an opening
and tube in the conical reflector immediately over the flame and from the Baid
tube into the top of the lamp. The said air and products of combustion escape
into the atmosphere through a series of annular spaces formed by three or other
number of short tubes of progressively diminishing diameter fixed in each other
somewhat after the manner of drawn out telescope tubes the respective diameters
of which leave annular spaces of considerable capacity between them.
The appliances constituting part of my invention-consist of carriers to be
employed in transporting the interiors of lamps where oil is used from the place
where they are trimmed and lighted to the case of the signal or other lamp. The
carrier consists of a thin metal case on a frame to the top of which a handle is
jointed for carrying it. The said case may be of a size suitable for carrying
either two three or four lamps. The lamps are placed in the carrier as in the
proper lamp case the light being concealed. A shield suspended from the handle
of the carrier screens the hand of the person grasping it from the heat of the
lamps.
By the use of carriers of the kind described there is practically no light shown
from the lamps while they are being transferred from the place where they are
trimmed and lighted to the signals or other destinations and the danger which
arises from lamps in transit being mistaken for the lamps of signals is avoided.
Dated this eighth day of September 1885.

page_text: Improvements in Railway Signal Lamps and other Lamps, and
in Appliances to be Used with Railway Signal Lamps and
other Lamps.
I SAMUEL TELFORD DUTTON of N° 1 Saint George's Square in the City of
Worcester Civil Engineer do hereby declare the nature of the said Invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :—
My improvements have reference principally to railway signal lamps and
appliances to be used with lamps made according to my invention but my said
invention is applicable wholly or in part to lamps other than railway signal lamps.
I will describe my invention in connection with a railway signal lamp. I make
the lens and the reflector of the lamp in the following manner. The whole of the
back of the lens is flat and the central portion of the front of the lens is convex,
the central part of the lens having the figure of an ordinary plano-convex lens.
Around the central part of the lens is a series of concentric zones the front faces of
which are convex the convexity of the zones diminishing progressively as the said
zones are situated more and more distant from the centre of the lens. Thus, the
radius of curvature of the zone immediately surrounding the central part of the
lens is somewhat longer than the radius of the front of the said central part of
the lens, the radius of the second zone is somewhat longer than that of the first
zone and so on, the radii of the zones increasing in length and the radial point in
distance from the plain side of the lens as the zones are more distant from the
centre of the lens. By this construction of lens the central portion refracts the rays
of light incident upon it into a cylindrical beam of light while the successive zones
refract the light incident upon them more and more outside the beam of the central
portion. The result of these refractions is to produce a beam of light having a
conical figure and visible within an area gradually widening from the lamp.
At the back of the flame is a concave reflector and surrounding the top and sides
of the flame is a reflector of a nearly conical figure the curvatures of the said
reflectors being such that the light incident upon and reflected by them conspires
with the refracted light to produce the conical beam of light herein before referred
to. Instead of the outline of the lens being circular it may be oblong its greatest
length being horizontal as the object is to produce a beam of light visible within an
extensive horizontal range but of limited range vertically.
The lamp may either burn oil or gaa When gas is used the oil reservoir and
hurner are removable. The lamp is provided with a bonnet or deflector for
directing a current of air to the flame. This deflector moves vertically. When the
lamp is removed from its case this deflector takes its lowest position resting on
the top of the reservoir and thus protecting the flame from the wind but when the
lamp is put in its place in the lamp case the bottom edge of the deflector coming
in contact with the false bottom of the case its further descent is prevented and as
the reservoir is depressed into its seat the air passages by which air is supplied to
the flame are opened.

page_text: To fit the lamp for burning gas a gas pipe furnished with any desired jet or
burner is fixed on the bottom of the lamp case the said pipe turning upon a joint
and being capable when not required to be used of lying flat on the bottom of the
слве. For use it is raised into a vertical position in which position its jet or
burner occupies the position of the jet of the oil lamp inside the reflector. The
vitiated air and products of combustion pass upwards through an opening and tube
in the conical reflector immediately over the flame and from the said tube into the
top of the lamp. The said air and products of combustion escape into the
atmosphere through a series of annular spaces formed by three or other number of
short tubes of progressively diminishing diameter fixed in each other somewhat
after the manner of drawn out telescope tubes, the respective diameters of which
leave annular spaces of considerable capacity between them.
The appliances constituting part of my invention consist of carriers to be
employed in transporting the interiors of lamps where oil is used from the place
where they are trimmed and lighted to the case of the signal or other lamps. The
carrier consists of a thin metal case on a frame to the top of which a handle is
jointed for carrying it The said case may be of a size suitable for carrying either
two three or four lamps. The lamps are placed in the carrier as in the proper
lamp case, the light being concealed. A shield suspended from the handle of the
carrier screens the hand of the person grasping it from the heat of the lamps.
I will now proceed to describe with reference to the accompanying Drawing the
manner in which my invention is to be performed.
Figure 1 represents in vertical section a railway signal lamp constructed
according to my invention and Figure 2 is a horizontal section of the same taken
through the centre of the lens; Figure 3 represents the lens detached from the
lamp; Figure 4 is a vertical section of the lamp and the reflector, the oil interior
being removed and the gas burner raised for use and Figure 5 is a front elevation
of the lamp; Figure 6 is an elevation of the interior detached and Figure 7 is a
front elevation of the reflector detached.
The same letters of reference indicate the same parts in the several Figures of
the Drawing.
a is the lens b is the rear part of the reflector giving diverging rays from centres
more remote than the flame of the lamp and 61, 6¹ are the side parts of the reflector
reflecting rays through centres nearer than the flame of the lamp, the course of the
reflected rays being approximately shown in Figures 1 and 2. A front elevation
of the reflector is shown in Figure 7. The reflector b, b³, 61 is mounted in a
movable inner case e³ the lamp interior case being marked e¹ (see Figure 1). The
sides 61, 6 of the reflector are made of such a shape as to spread the light over the
lens a; c is the oil cistern or reservoir mounted with a burner as usual; c¹ is the
ventilating plate or bonnet raised above the oil cistern c by coming in contact with
the fixed false bottom c². By means of the said plate or bonnet c¹ additional
ventilation is given when the lamp interior is in its place.
The way in which the currents of air pass between the ventilating plate or
bonnet c¹ and the oil cistern c and are directed onto the flame is shown in Figure 1
and the direction of the air currents is indicated by arrows.
In the detached view of the interior represented in Figure 6 the ventilating
plate c¹ is shown in its lowest position, the air space over the oil cistern c being
closed.
The ventilating plate may if required be arranged at the sides or under the
cistern c; d, d¹, dare the annular spaces formed by concentric tubes at the top of
the body of the lamp for carrying away the products of combustion from the lamp,
the said products of combustion passing upwards through the chimney e of the
interior lamp case e¹; f is the gas bracket and burner represented in Figure 1
lying folded on the bottom of the lamp case out of the way of the oil interior but
the said gas bracket and burner is represented in Figure 4 raised into a vertical
position for use, the oil interior being removed from the lamp. The reflector b, b'

page_text: is made of any suitable material for use with gas, as for example an enamelled or
opal lined internal surface may be employed.
The spreading rays of light both horizontal and vertical are approximately.
shown in dotted lines in Figures 1 and 2. By referring to the horizontal section
Figure 3 of the lens it will be seen that the zones are formed from the varying
radial points g, g¹, g³, g³ and g', h being the position of the flame, the centre part
of the lens being made suitable for that focus to give nearly parallel rays, the
outer zones producing rays more or less divergent.
The usual small lens at the back of the lamp is for the signalman to see at night
that his signal is acting.
The lens described may be modified in form or outline and suited to the position
of the light and reflector and extent of radiation of light required and the said
lens may be applied to various kinds of lamps. The reflector may also be modified
so as to adapt it to the particular kind of lamp with which it is to be used.
For the purpose of illustration I have shown in Figures 8, 9, 10 and 11,
Figures 8 and 10 being vertical sections and Figures 9 and 11 horizontal sections,
two types of lamps to which lenses and reflectors made according to my invention
are applied, the parts being marked with the same letters of reference as corre-
sponding parts in Figure 1.
Although I prefer to make the lens oblong as shown yet it may be equal or
unequal on each side of the horizontal line and the sides of the reflector may be
made to give rays distributed on the area of the lens equally or more in one place
than another as required. In the Drawing the lens is shown unequal on each side
of the horizontal line, the lower half of the lens being the larger.
The lens and reflector herein before described may be adapted to existing lamps
of varying forms either separately or combined.
I will now describe the appliances or carriers employed in transporting the
interiors of lamps where oil is used from the place where they are trimmed and
lighted to the case of the signal or other lamp.
Figures 12, 13 and 14 are respectively a side elevation, a vertical cross section
and a half plan, of an appliance or carrier constructed according to my invention
for carrying the oil interiors after the wicks have been trimmed to the signal posts ;
i is the case of the carrier open at top and bottom and k is the jointed handle for
carrying the same; k¹ is the guard under the bow of the handle to protect the hand
of the person transporting the carrier and interiors. At the base of the carrier is
the cross piece and feet for supporting the carrier off the ground; m, m² are lamp
interiors within the case i of the carrier.
The lamp interiors m¹ m² are introduced into and removed from the case i of
the carrier from its open top, the bottoms of the lamp interiors when in the carrier
resting on the base of the said case as best seen in Figure 13.
By the use of carriers of the kind described and represented there is practically
no light shown from the lamps while they are being transferred from the place
where they are trimmed and lighted to the signals or other destinations and the
danger which arises from lamps in transit being mistaken for the lamps of signals
is avoided.
Having now particularly described and ascertained the nature of my invention
and the manner in which the same is to be performed I declare that I claim as
my invention of "Improvements in railway signal lamps and other lamps and in
appliances to be used with railway signal lamps and other lamps" :-
First The construction of lenses for railway signal and other lamps herein
before described and represented in the accompanying Drawing, that is to say,
surrounding or partly surrounding a central plano convex lens by prismatic zones
the convexity of the said zones diminishing as the said zones are situated more and
more distant from the centre of the lens.
Secondly-The reflector for railway signal and other lamps herein before
described and illustrated in the accompanying Drawing, the said reflector having

page_text: :
nearly the figure of a hollow cone the direction of the rays of light reflected by
the reflector coinciding or nearly coinciding with the rays directly radiated upon
the lens from the flame and conspiring with the said rays radiated from the flame
to produce a divergent beam of light of great intensity.
Thirdly The bonnet or deflecting plate for directing a current of air upon the
flame the said bonnet or deflecting plate being constructed and arranged in the
manner herein before described and illustrated in the accompanying Drawing.
Fourthly The adaptation of a gas burner to railway signal and other lamps in
combination with a reflector as described, the said burner being so jointed that it
may either be folded flat on the bottom of the lamp case when not required for
use or raised into a vertical position when gas is to be burned in the lamp as
herein before described and illustrated in the accompanying Drawing.
Lastly The construction and arrangement of the parts of appliances or carriers
for carrying two or more lighted oil lamps or lamp interiors from the place where
they are trimmed to their destination without exhibiting a light in transit as
herein before described and illustrated in the accompanying Drawing.
Dated this Twenty second day of May 1886.