Year: 1887

page_text: Date of Application, 7th June, 1887
Complete Left, 3rd Mar., 1888
Complete Accepted, 13th Apr., 1888
1 SAMUEL TELFORD DUTTON of Marl Bank in the City of Worcester Civil
Engineer do hereby declare the nature of this Invention to be as follows:-
:-
My invention consists of the improvements bereinafter described in railway signal
lamps and appliances for the said lamps.
My improvements refer in part to the invention described represented and claimed
in the specification of Letters Patent granted to me dated September 8th 1885
No. 10,620.
The improvements in the invention before referred to have for their object greater
convenience in keeping in order and properly cleaning the lenses and spectacle glasses
of railway signal lamps lighted by gas and also to facilitate the change from using
gas to oil in case the supply of the former combustible fails.
Instead of fixing the lamp in its position on the signal post and attaching to the
bottom of the lamp the folding down gas bracket as described in the specification of
the patent before referred to I make the lamp portable that is capable of being lifted
away from its position on the post and I connect the folding down gas bracket to the
lamp bracket fixed on the post or to an adjustable part of the lamp bracket in any
convenient way so that when the gas bracket is folded down into a horizontal position
its level will be situated below the bottom of the lamp. The lamp bracket or the
adjustable part of the lamp bracket has a vertical carrier on which the lamp is sup-
ported which carrier engages with a corresponding recess on or in the lamp. By
lifting the lamp vertically it can be taken off the said carrier and removed from the
gas bracket which bracket can then be turned down. When the gas bracket is in its
folded down position the lamp can be lifted off the bracket on the post for the
purpose of cleaning or renewing its oil interior and used like an ordinary lamp
burning oil.
By these means railway signal lamps burning gas are made more convenient in
use and offer greater facilities for changing the combustible than ordinary fixed
lamns.

page_text: My improvements consist further as follows :-
In railway signal lamps as ordinarily constructed a small plano convex lens mounted
on a slide having motion horizontally is placed at an opening in the back of the lamp
immediately. opposite the flame. The said lens indicates to the signalman the cou-
dition of the lamp and the working of the signal at night but the field within which
a sufficient light can be observed is very limited and where lamps are interchanged
there is often wanting that coincidence between the position of the lens and that of
the flame necessary to the proper action of the said lens.
In order to remedy this difficulty with respect to interchangeable lamps particularly
portable ones I adopt the following arrangement. In place of the ordinary lens
referred to I employ a fixed lens either of the forin of the frustrum of a cone or of
one of the forms herein after referred to. The base of the cone is presented to the
flame and the light radiated from the flame falling upon the inner surface of the cone
suffers total reflection each ray after total reflection passes from the glass into the air
undergoing refraction at the common surface of the glass and air. The result of this
reflection and refraction is a divergent beam of light the field of which can be made
to include so large an angle that the signalman can see the light when he is at a con-
siderable distance from the axial line of the beam. The lens instead of being circular
in cross section may be oblong in cross section which figure will give a beam of light
diverging largely horizontally but diverging less vertically.
When the lens is made oblong in cross section its vertical sides are inclined at the
angle necessary to produce the required divergence.
The face of the lens at which the light enters and from which it emerges may either
be plain or curved.
Dated this Seventh day of June 1887.
W. T. WHITEMAN,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Railway Signal Lamps and Appliances for the
said Lamps.
I SAMUEL TELFORD DUTTON of Marl Bank in the City of Worcester, Civil
Engineer, do hereby declare the nature of my 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 consists of the improvements hereinafter described in railway Cignal
lamps and appliances for the said lamps.
My improvements refer in part to the invention described represented and
claimed in the specification of Lettera Patent granted to me dated September 8th
1885 No. 10620.
The improvements in the invention before referred to have for their object greater.
convenience in keeping in order and properly cleaning the lenses and spectacle glasses
of railway signal lamps lighted by gas and also to facilitate the change from using
gas to oil in case the supply of the former combustible fails.
Instead of fixing the lamp in its position on the signal post and attaching to the
bottom of the lamp the folding down gas bracket as described in the specification of
the patent before referred to, I make the lamp portable, that is, capable of being lifted
away from its position on the post and I connect the folding down gas bracket to the
lamp bracket fixed on the post, or to an adjustable part of the lamp bracket, in any
convenient way so that when the gas bracket is folded down into a horizontal position
its level will be situated below the bottom of the lamp. The lamp bracket or the
adjustable part of the lamp bracket has a vertical carrier on which the lamp is sup-
ported which carrier engages with a corresponding recess on or in the lamp. By
lifting the lamp vertically it can be taken off the said carrier and removed from the
gas bracket which bracket can then be turned down. When the gas bracket is in its
folded down position the lamp can be lifted off the bracket on the post for the purpose
of cleaning or renewing its oil interior and used like an ordinary lamp burning oil.
By these means railway signal lamps burning gas are made more convenient in use
and offer greater facilities for changing the combustible than ordinary fixed lamps.
My improvements consist further as follows:-In railway signal lamps as ordinarily
constructed a small plano-convex lens mounted on a slide having motion horizontally
is placed at an opening in the back of the lamp immediately opposite the flame.
The said lens indicates to the signalman the condition of the lamp and the working.
of the signal at night but the field within which a sufficient light can be observed
is very limited and where lamps are interchanged there is often wanting that
coincidence between the position of the lens and that of the flame necessary.to the
proper action of the said lens.
In order to remedy this difficulty with respect to interchangeable lamps particularly
portable ones I adopt the following arrangement. In place of the ordinary lens

page_text: referred to I employ a fixed lens either of the form of the frustrum of a cone or of
one of the forms hereinafter referred to. The base of the cone is presented to the
flame and the light radiated from the flame falling upon the inner surface of the cone
suffers total reflection; each ray after total reflection passes from the glass into the
air undergoing refraction at the common surface of the glass and air. The result of
this reflection and refraction is a divergent beam of light the field of which can be
made to include so large an angle that the signal man can see the light when he is at
a considerable distance from the axial line of the beam. The lens instead of being
circular in cross section may be oblong in cross section which figure will give a beam
of light diverging largely horizontally but diverging less vertically. When the lens
is made oblong in cross section its vertical sides are inclined at the angle necessary to
produce the required divergence.
The face of the lens at which the light enters and that from which it emerges may
either be plane or curved.
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, Figure 2 in side elevation and Figure 3 in
back elevation, a movable or detachable railway signal lamp and appliances used
therewith constructed according to my invention, Figures 1 and 2 exhibiting the
folding gas bracket carrying the burner in an upright position for use when
burning gas.
Figure 4 represents in plan the supporting appliances of the lamp (the lamp being
detached therefrom) and exhibits the gas bracket folded down horizontally when
burning oil in the lamp.
The same letters of reference indicate the same parts in the several Figures of the
drawing.
The bracket supporting the lamp and the folding gas bracket consists of two parts
marked respectively a and a'. The part of the bracket is fixed permanently to the
signal post and the part a¹ is removable from and adjustable upon the fixed part a.
The said adjustable part a' of the bracket carries the folding gas bracket c which is
capable of swivelling in the barrel or socket e carrying the gas supply pipe c², which
pipe c² is attached or coupled by a screw nut to the gas service on the signal post b.
On the adjustable part a¹ of the supporting bracket is the carrier pin a² by which the
lamp d is supported in its position on the bracket, the said pin a' taking into a guide
or recess d¹ made inside the body of the lamp as represented, or outside the body of
the lamp. The fixed part a of the bracket is furnished with a slot at in which the
lower part of the carrier pin a² and gas supply pipe c² work. By sliding the said
pin a² and pipe c² in the slot at the position of the part al of the bracket may be
adjusted on the fixed part a and fixed in its adjusted position by the screw nut a³
which is screwed on the lower end of the carrier pin a³.
When the signal lamp is lighted by gas the parts are arranged in the manner
represented in Figures 1 and 2, that is, the gas bracket c is in its vertical or upright
position. By lifting the lamp d vertically it can be removed from the carrier pin a
for cleaning it and the spectacle glasses used in combination with the said lamp and
replaced in the position represented.
When the lamp is to be lighted by oil the lamp is lifted from the carrier pin a³ and.
the gas bracket c is turned down into a horizontal position as represented in Figures 3
and 4. The body of the lamp is now supplied with the usual oil interior and the lamp
is replaced upon the carrier pin a² with the gas bracket c in its folded down position.
The lamp when burning oil can be lifted from the carrier pin a² for cleaning or
trimming it and used like an ordinary lamp burning oil. Thus the lamp can be
changed for burning oil or gas without disconnecting the gas fittings carried by the
bracket.
Instead of connecting the folding down gas bracket to an adjustable part of the
lamp supporting bracket carried by the signal post the said folding down gas bracket
may be carried by a lamp supporting bracket made in one piece and fixed to the signal

page_text: post but I prefer to use the arrangement, represented as by the use of that arrange-
iment the distance of the lamp from the signal post can be adjusted with great
nicety.
I will now describe my improved fixed back light lens or reflector of the signal
lamp.
The said lens is represented in combination with the first part of my invention in
the lamp Figures 1, 2 and 3 and in horizontal section in Figure 5, the said lens
having a conical figure: Figure 6 represents an end elevation of the lens separately:
Figures 7, 8, 9 and 10 represent the same construction of lens but modified in shape
as hereinafter explained.
e is the back light conical lens or reflector of the lamp and fis the frame or sockot
fixed to the lamp case in which frame or socket the lens is mounted being preferably
embedded in plaster of Paris f¹. The lens e acts both by refraction and reflection
the less divergent portion of the light impinging on its inner face and emerging from
its outer face without falling upon the internal conical surface undergoing refraction
only, while the more divergent portion of the light which falls upon the internal
conical surface of the lens undergoes both refraction and reflection.
e is the inner plane surface of the lens receiving the rays of light from the flame
at ce is the internal conical surface of the lens by which surface the rays of light
falling on it are totally reflected towards the front surface e³ and more or less refracted
therefrom according as the last named surface e' is concave, plane or convex as may be.
required. In Figure 5 the dotted lines g, g represent approximately the rays of light
which are totally reflected from the surface and the dotted lines g', show the
rays of light directly radiating through the central portion of the lens without
reflection. All the rays of light from the flame falling upon the inner face of the
lens e will either pass directly through the said lens or fall upon and be internally
reflected by the conical surface of the lens.
In the modified lens represented in Figures 7 and 8 its vertical sides are flattened
and in the other modified lens represented in Figures 9 and 10 it is oblong in cross
section. By the use of the lenses Figures 7, 8, 9 and 10 a greater horizontal
divergence of the light is produced than by the use. of the lens Figures 5 and 6.
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 appliances for the said
lamps"
First. The combination with or adaptation to a supporting bracket carried by the
signal post, of a folding gas bracket to be used with the body or case of the lamp
when burning gas, the said supporting bracket and folding gas bracket being used
in conjunction with a portable or movable lamp body or case with which the ordinary
oil interior can be used when the folding gas bracket is turned down horizontally
and oil is to be burned in the lamp, substantially as herein before described and
illustrated in Figures 1, 2, 3 and 4 of the accompanying Drawing.
Secondly. Forming the backlight lenses of railway signal lamps of a conical figure
and fixed in the back of the lamp so that the light from the flame falling upon the
lens shall in part pass directly through or only undergo refraction by the lens and in
part undergo total reflection from the internal conical surface of the lens as in
Figures 1, 2, 3, 5 and 6, together with the modifications represented in Figures 7, 8, 9
and 10 substantially as and for the purpose hereinbefore described and illustrated in
the accompanying Drawing.
1 1000