IMPROVEMENTS IN RAILWAY CARRIAGE ROOF LAMPS
Year: 1882

page_text: LETTERS PATENT to Henry Defries of the firm of J. Defries. and Sons of
No. 147, Houndsditch in the City of London, for an
"IMPROVEMENTS IN RAILWAY CARRIAGE ROOF LAMPS
"
invention of
PROVISIONAL SPECIFICATION left by the said Henry Defries at the
Office of the Commissioners of Patents on the 26th April 1882.
HENRY DEFRIES, of the firm of J. Defries, of No. 147, Houndsditch in the City
of London. "IMPROVEMENTS IN RAILWAY CARRIAGE ROOF LAMPS '
"
My invention relates to improvements in Railway Carriage Roof Lamps whereby
the wick is prevented from carbonizing or becoming deteriorated so rapidly as in
ordinary Railway Carriage Roof Lamps the breakage of the chimney glasses by
reason of expansion and contraction under the influences of temperature is wholly
obviated a better downward reflection of the light obtained and a more regular
current of air directed to the flame.
I propose to use a chimney made of two curved pieces of glass set in a metal
frame so that they form a chimney a draught tube preferably of an oval form
but divided vertically into two or more distinct parts.
I also propose to make the bottom of the frame carrying the glass chimney of
such a form as to constitute a dome or cone to which I prefer however should be
less desired than ordinary cones, and the inside of which I polish or otherwise
make a reflector for directing light downwards from the flame.
My divided glass tube or chimney may be of any suitable height and the top of
the frame be joined by hinge or otherwise to a metal tube preferably of oval form
and secured thereon by a spring or other fastening so that the metal tube may be
moveable on the frame for the insertion or removal of the parts forming the glass
chimney.
At a certain point of this metal draught tube I propose to place a perforated
plate or any suitable stop or stops so that when the whole of this arrangement is
put into the lamp this plate or stop piece or pieces will rest upon an inner case
such as exists in ordinary Railway Carriage Roof Lamps thus supporting the whole

page_text: of the arrangement above described and suspending the cone or dome at a regulated
distance over the flame thus the wick holder is not onclosed or surrounded by. a
metal or other casing but the whole of its outer surface left exposed to be cooled
by the air drawn into the Lamp for the purpose of combustion, the result being
that the lower part of the wick is kept cooler and will last much longer giving an
equally bright light until wholly consumed.
I may use my suspended chimney made of two or more pieces of Glass without
the cone or I may in some cases not suspend my divided glass chimney but fix it
in a suitable frame or gallery carried by the burner.
In order to prevent the flickering of the light which occurs with ordinary Railway
Carriage Roof Lamps when the Train is running at a great speed and to obtain a
steady and constant bright light.
I make below the casing which carries the Reservoir with perforations near the
top and the cover rim of the Lamp with an inner fange deep enough to come on to
or nearly on to the top of the Reservoir when the cover rim is down
The casing carrying the Reservoir resting upon a ring or projection around the
inside of the outer case the air entering by the perforations under the outer brass
rim cannot descend directly to the flame between the inner and outer casing but
_striking against the above mentioned flange will be directed from thence through
-the-perforations, which are below the said supporting-ring-and-then-descend to the
flamme in a steady current.
--

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Defries in the Great Seal Patent Office on the
25th October 1882.
HENRY DEFRIES, of the Firm of J. Defries & Sons of 147 Houndsditch in the
City of London "IMPROVEMENT IN RAILWAY CARRIAGE ROOF LAMPS
My invention relates to improvements in railway carriage roof lamps whereby
the wick is prevented from carbonizing or becoming deteriorated so rapidly as in
ordinary railway carriage roof lamps, the breakage of the chimney glasses by
reason of expansion and contraction under the influences of temperature is wholly
obviated, a better downward reflection of the light obtained and a more regular
current of air directed to the flame.
To prevent the rapid carbonization and deterioration of the wick I suspend a
draught tube or chimney so that its bottom, preferably cone shaped, comes slightly
above, or level with, the top of the wick holder, the outer surfaces of which I thus
leave freely exposed to the cooling influence of the air constantly being drawn into
the lamp for combustion and escaping by this draught tube.
I obviate the breakage of the glass, forming the whole or part of my suspended
draught tube or chimney, under the action of expansion and contraction, by
dividing the glass vertically into two or more sections set freely in suitable frame
work; and I may make the lower part of this framework a reflector, preferably of
a slightly domed shape to direct the air draught well around the frame.
I also direct a more regular current of air upon the frame by a particular con-
struction of the casing which carries the reservoir and of the cover rim of the lamp,
together with a special arrangement of the perforations therein.
In order that my improvements may be fully understood I will now proceed to
describe them by reference to the accompanying Sheet of Drawing, upon which :—
Figure 1 represents an elevation of a railway carriage roof lamp embodying my
improvements.
Figure 2 a vertical section, and,
Figure 3 a plan with the lid thrown back,
Figure 4 being a view of tho draught tube or chimney detached and drawn full
size, and,
Figure 5 a sectional plan of same at Z Z figure 4.
Figure 6 being an enlarged view showing the arrangement for regulating and
directing the inward current of air.
Similar letters of reference indicating similar parts in each of the figures
respectively: :
A indicates the glass of the draught tube or chimney. B ita metal frame-C the
dome shaped reflector at bottom of glass_frame-D perforated plate supporting
draught tube or chimney in the lamp-E metal upper part of draught tube-
F spring or fastening securing tube E to frame B-G guides for draught tube
H casing for oil reservoir-I oil reservoir-K inner flange on cover rim of lamp-
L lamp glass-M body of lamp-N wick holder or burner-0 perforations in outer
case-P perforations in casing B-Q projection or ring supporting casing H.
The arrows indicate the direction of the current of air entering and leaving the
lamp.
At Figures 4 and 5 it will be seen that the lower part of the draught tube or
chimney is made of two curved pieces of glass A A, set in the metal frame B, so
that they form a chimney of an oval form but divided vertically into two distinct
parts, or glass sections, so set into their framme as to permit of expansion and con-
traction. I find this oval shape of tube or chimney answer well, but it may be of

page_text: any suitable form and of any number of sections of glass. I may in some cases
make my glass sections with a flanged top so that they may be suspended thereby,
being fixed in any suitable frame or catch.
It will also be seen that the bottom of the frame B carrying my divided glass
chimney is of such a form as to constitute the dome or cone C, which I prefer
however should be less domed than the cones carried upon ordinary burners, and
the inside of which I polish or otherwise make a reflector for directing light
downwards from the flame.
My divided glass tube or chimney may be of any suitable height and I prefer to
join the top of its frame by hinge, as shown in the drawing or otherwise, to the
metal tube E, preferably of the samo oval form as the glass chimney, and secured
thereon by the spring F, or other suitable fastening, but always so that this metal
tube may be moveable on the frame B for the insertion or removal of the sections
or parts forming the glass chimney.
The perforated plate D with which the draught tube E is provided rests upon
the inner case existing in ordinary railway carriage roof lamps, and by its position
upon the tube E suspends the cone or dome at a regulated distance over the flame.
Thus, the air for combustion is directed upon the flame, the wick-holder not being
cuclosed or surrounded by a metal, or other casing, but the whole of its outer
surface being left exposed to be cooled by the air drawn into the lamp for the
purpose of combustion, the result being that the lower part of the wick is kept
cooled and the wick lasts much longer, giving an equally bright light until wholly
consumed.
Although I prefer using a draught tube or chimney of glass in sections divided
vertically and with metal tube superposed, the chimney or draught tube night be
of such glass sections in its entire height, and I do not limit myself to the use of
the perforated plate D, whether on the metal tube or on the glass frame, for the
purpose of suspending the chimney, but use any kind of stop or stops, or means of
suspension, which I may find suitable, so that the suspended chimney may be
attached either fixed or loosely at any suitable part of the lamp; and, if desired, I
might even carry my improved drauglit tube or chimney upon any suitable support
or supports from the burner.
I may use my suspended chimney made of two or more pieces of glass set freely
in a metal or other suitable frame without making the lower part of the frame in
the form of a conc, or using it as a reflector.
To prevent the flickering of the light which occurs with ordinary railway carriage
roof lamps when the train is running at a great speed, and to obtain a steady and
constant bright light, I make the casing H which carries the reservoir I with
perforations P. and the cover rim of the lamp with an inner flange K, deep enough
to come on to, or nearly on to, the top of the reservoir I when the cover rim is
down. As the casing carrying the reservoir rests upon the ring or projection Q
around the inside of the outer case, the air entering by the perforations O under
the outer brass rim cannot descend directly to the flame between the inner and
outer casing, but, striking against the above mentioned flange K will be directed
from thence through the perforations P, which are below the said supporting ring,
and then descend to the flame in a steady current.
Having now described and ascertained the nature of my said Invention and in
what manner the same is or may be performed, I desire it to be understood that I
may use my several improvements in combination as shewn on the accompanying
Drawings, or separately and applied to any construction of railway carriage roof
lamp to which either, or any of them, may be found applicable; that I do not
limit myself to any particular mode of suspending my vertically divided glass
chimney, nor to any number shape or dimensions of glass sections forming this
chimney, but may vary these and other details while retaining the essential
characteristics of my several improvements, and that what:
I claim as secured to me by the hereinbefore in part recited Letters Patent is :-
Firstly In a railway carriage roof lamp, the use of a draught tube or chimney

page_text: made of vertical sections of glass set in a suitable frame and suspended at a
regulated distance from the wick holder so as to leave the surfaces of this latter
freely exposed to the cooling effect of the inward draught, substantially as herein-
before described and for the purpose specified.
Secondly-In a railway carriage roof lamp, the use of a draught tube or
chimney made of two or more sections or pieces of glass divided, vertically and
set so as to permit their expansion and contraction, substantially as hereinbefore
described.
Thirdly-In a railway carriage roof lamp, the combination of a vertically
divided glass tube or chimney with a superposed metal tube or chimney, the whole
being suspended within the lamp substantially as herein described and shown on
the Drawings, or by any suitable means of suspension.
Fourthly-In a railway carriage roof lamp having a glass draught tube or
chimney in vertical sections, constructing the lower part of the frame carrying
these sections so that it forms a cone, and, if desired, a reflector, substantially as
herein before described.
Lastly. A railway carriage roof lamp arranged, constructed and combined as
herein before described and illustrated on the accompanying Sheet of Drawing.
In Witness whereof I the said Henry Defries have hereunto set my land and
seal this Twenty fourth day of October in the year of Our Lord One
thousand eight hundred and eighty two:
FRIEDY
ORDINA