IMPROVEMENTS IN RAILWAY CARRIAGE LAMPS
Year: 1876

page_text: LETTERS PATENT to William Perkins, of Ampthill Square, in the County of
Middlesex, Chemist, for the Invention of "IMPROVEMENTS IN RAILWAY
CARRIAGE LAMPS."
Sealed the 14th October 1876, and dated the 19th April 1876.
PROVISIONAL SPECIFICATION left by the said William Perkins at the Office
of the Commissioners of Patents on the 19th April 1876.
WILLIAM PERKINS, of Ampthill Square, in in the County of Middlesex, Chemist.
"IMPROVEMENTS IN RAILWAY CARRIAGE LAMPS."
The object of this Invention is to make cheap and efficient railway carriage lamps
to burn hydrocarbon oils, whether of high or low specific gravity, without the aid
of glass chimnies, also to effect an economy in the manufacture of the lamp.
These objects I attain as follows:-Instead of placing the oil reservoir either
round the casing of the lamp, or inside at the bottom of the glass globe, or outside
at the bottom of the glass globe, or partly in and partly out and surrounded by an
air chamber as heretofore, in all of which cases the heated products of combustion
have been brought more or less in contact with the oil holder, I place the oil holder
outside the glass globe and below the air chamber. By so doing I am enabled to
reduce the size of the glass globes very considerably, thus diminishing their first
cost and reducing the risk of their breakage to a minimum. Furthermore by so
placing the oil chamber the surrounding air plays freely upon its whole surface and
keeps its contents comparatively cool. The form of the reservoir is immaterial, but
I find a semisphere to be a very convenient shape. Upon this semisphere I fix by
any of the well-known means a burner and wick carrier, and around these I form
an annular air chamber which carries a dome or deflector. To the sides of this
small air chamber I attach two air tubes, which ascend outside the glass globe and
pass through and are soldered to an annular reflector which surrounds the glass
globe which rests as usual on the gallery of the burner. By this arrangement the
reflector is unaffected by the burner and consequently is always bright and requires
scarcely any cleaning. The two air tubes serve the double purpose of furnishing
the necessary supply of fresh air for supporting combustion and of connecting the
burner with the case. A central metal cylinder with a small reflector attached
internally to its lower edge is connected by a bayonet joint to the outer reflector
[Price 6d.

page_text: and it thus serves to firmly hold the glass globe and draw all the parts tightly
together. This cylinder also carries a short central metallic chimney. The air
supply may be drawn either from the inside or the outside of the carriage; in the
latter case the annular space between the cylinder and the case must be protected
so as to prevent the too rapid ingress and egress of the air, while in the former case
it acts partly as a ventilator to the carriage. The oil reservoir may be made of
metal or of stout glass. In the latter case the oil will be kept at a lower temperature
than in the metal holders.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said William Perkins in the Great Seal Patent Office on the 19th October 1876.
WILLIAM PERKINS, of Ampthill Square, in the County of Middlesex, Chemist.
"IMPROVEMENTS IN RAILWAY CARRIAGE LAMPS."
The objects of this Invention are to make cheap and efficient railway carriage
lamps to burn hydrocarbon oils, whether of high or low specific gravity, without
the aid of glass chimnies, and to effect economy in the making and working of the
lamps. These objects I attain as herein-after described.
The oil reservoir or holder has hitherto been placed either around the casing of
the lamp, or inside at the bottom of the glass globe, or outside at the bottom thereof,
or partly in and partly out, and surrounded by an air chamber, in all of which cases
the heated products of combustion have been brought more or less in contact with
the oil holder.
According to my improvements (which are illustrated in their combination on
the accompanying Drawing, of which the right hand half represents an exterior
elevation, and the left hand half a central sectional elevation of the improved lamp).
I place the oil holder 1 outside the glass globe 2 and below the air chamber 3, this
enables me to use glass globes of a very much.smaller size than those hitherto used,
which considerably lessens the first cost of the lamp and reduces the risk of the
breakage of the globe to a minimum. Furthermore the contents of the holder 1 are
kept comparatively cool as the surrounding air is enabled to play freely around and
upon the whole exterior surface of the holder. The holder may be made of metal or
of stout glass, in which latter case the oil will be kept at a lower temperatore than
if the holder were made of metal. The form of the holder is immaterial, but that
of a semisphere or that illustrated on the annexed Drawing I find to be very
convenient. Upon the holder 1 I apply by any usual means a burner 4 and a wick
carrier 5, and around these I form an annular air chamber 3 on which I fix a dome
or deflector 7. To opposite sides of the air chamber 3 I attach two air tubes S
which ascend outside the globe 2 and pass through and are soldered to an annular
reflector 9 forming the bottom of the case 11 and surmounting the globe 2 which
rests as usual on the gallery 10 of the burner 4. With this arrangement the
reflector 9 is unaffected by the products of combustion and consequently is always
bright and requires scarcely any cleaning. The tubes 8 thus also serve the double
purpose of furnishing the air chamber 3 with the necessary supply of fresh air for
supporting combustion and of connecting the holder 1 (which screws on to the bottom
of the air chamber and may be secured by any suitable locking device) and its
appurtenances with the casing 11. A central metal cylinder 12 is connected by an
ordinary bayonet joint (not shown on the annexed Drawing) to a rim 14 rising
from the reflector 9, and it thus serves to firmly hold the globe 2 (which is otherwise
secured and made air-tight by cement at 6) and keep the parts well together so as
to prevent them jarring; or the cylinder 12 may be pressed upon its seating 18 by
means of a coiled or other spring attached to the casing 11 and pressing down upon
the top of the cylinder 12; this cylinder also carries a short central metallic
chimney 15: The air supply may be drawn either from the inside or outside of the
carriage through holes 19 in the case 11. The tubes 8 and the diaphragm 16 being
perforated with holes 17 in order to retard the inflowing current of air so that it

page_text: shall not render the flame unsteady and flickering. In cases where the protector
tops on the railway carriages are carried a more than usual distance above the
carriage, or in which they are made with very large air holes, I provide the neck or
band 13 with a perforated plate 19* and a close plate 20 which prevents the flame
being blown out or about.
Having now described the nature and objects of my said Invention for "Improve-
ments in Railway Carriage Lamps," together with the manner in which the same
is to be or may be carried into practical effect, I would remark in conclusion that
I claim as my Invention, the novel and peculiar combination and application in a
railway carriage lamp of an oil holder, connected to and arranged below an air
chamber with a small glass globe surmounting and connected to the air chamber and
surmounted or encircled by a reflector, and I also claim the further combination
therewith of the various other described subsiduary improvements, substantially as
described and as illustrated on the annexed Drawing.
In witness whereof, I, the said William Perkins, have hereunto set my hand
and seal, this Seventeenth day of October, in the year of our Lord One
thousand eight hundred and seventy-six.
Witness,
BRISTOW HUNT,
Solicitor and Patent Agent,
5, Serle Street,
Lincoln's Inn.
WM. PERKINS. (L.S.)