IMPROVEMENTS IN AND APPLICABLE TO LAMPS, TO BE USED ON RAILWAYS AND FOR OTHER PURPOSES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by John Thomas at the Office of the
Commissioners of Patents on the 15th May 1880.
JOHN THOMAS, of 567, Caledonian Road, Holloway, in the County of Middlesex.
"IMPROVEMENTS IN AND APPLICABLE TO LAMPS, TO BE USED ON RAILWAYS AND
FOR OTHER PURPOSES."
My Invention relates, in the first place, to "roof lamps" for lighting railway
carriages, and consists in constructing such lamps in the manner hereinafter stated.
The body or case of the lamp is of the usual form, but made with a separate
The oil cistern
body or case, which supports the burner inside the ordinary case.
is placed outside and on the top of the said inner body, being supported thereon by
means of pillars of cat gut, similar to those described in the Specification of a
Patent granted to me, and bearing date 13th May 1879, No. 1901, such pillars
being non-conductors of heat and preventing vibration. The cistern is made on
the principle known as the "bird fountain," and is covered on the inside of the
bottom with a layer or layers of cotton cloth or other suitable material, in order
to prevent the formation of bubbles in the oil, and it is also divided into
compartments with apertures leading from one to another. The oil is drawn from
the cistern to supply the burner by means of a syphon, made as described in the
Specification of a Patent granted to me, and bearing date 12th Oct., 1876,
No. 3953, by which means is regulated the supply of only the exact quantity of
oil required for consumption. The oil drips into a tube, which is fixed at bottom
into a collar or short tube of ivory or hard wood, for the purpose of insulating the
syphon from the heat of the lamp. The oil is thence conveyed through a tube
situated so that the oil therein is caused to be heated by its contiguity to the
flame before reaching the burner.
In order to prevent the overflow of oil when the lamp is not in use a valve is
employed which consists of an U tube, the arms of which are a little shorter than
the depth of the oil cistern. The said arms terminate in cups, each holding the
same quantity of oil as the tubes, one arm being in communication with the
interior of the cistern and the other being open to the atmosphere.
The burner consists of two metal discs or plates, one of which is hollow and
fixed in connection with the oil tube, the other being moveable, but fitting to the
fixed one by means of a central pin and spring. A piece of cotton cloth or wire
gauze is inserted between them and receiving the oil through a hole or holes
formed in the face of the hollow disk becomes thereby saturated, and forms a
means of lighting the lamp. This arrangement of burner admits of burning mineral
oil safely without a wick, the supply of oil being regulated as required by the
syphon, which is kept cool by being placed outside the lamp casing.
supplied to the burner by two, bent tubes fixed at top to the inner body of the
lamp, and receiving air from the interior of the said body, the lower ends
Air is

page_text: terminating in two cup shaped pieces, the edges of which are separated only by a
short intervening space. The said metal discs or burner are placed in the spherical
chamber formed by the two cup-shaped pieces, the faces of the discs being fixed in
the same plane as the opening between the edges of the said cup shaped pieces.
Over the flame is fixed a reflector having an aperture in the centre, and over which
aperture is placed a metal chimney, as usual, for the escape of the products of
combustion.
Another arrangement of burner has a ring like burner, suspended by the oil tube
in a horizontal position in the centro of the glass, basin, or dish, Air is supplied
by tubes similar to those already mentioned, but which terminate in a central
vertical tube under the burner, which has a metal plate fixed over it in order to
deflect the air on to the flame. Or a small cup shaped glass with an aperture in
the bottom is made to surround the central air tube and burner, extending upwards
to the reflector. Air being drawn through the aperture in the glass to the flame,
the branch tubes in this case are not required.
My Invention relates, in the second place, to lamps that are exposed to winds or
violent currents of air, and consists in the node hereinafter described of protecting
the flame of the lamp from such winds or currents of air.
A thin plate of mica, or talc, or sheet metal is suspended between two thicker
plates of metal, these latter being fixed nearly upright but inclining towards each
other, thus, these plates of mica or sheet metal being free to vibrate between
them. The said thicker plates have apertures formed in them for air to pass
through, such apertures being liable to be covered or closed by the vibrating plate.
One or more of these valves is or are placed near the bottom of the lamp case, air
being admitted thereto only through the apertures of the valves.
My Invention relates, in the fourth place, to a mode of regulating with precision
the size of the flame of a lamp, and consists in corrugating radially the inside face
of the milled edged button or thumb piece usually fitted to the spindle of the wick
holder, such button being enlarged for the purpose. A spring with a projecting
knob on the end is so fixed that the knob can be forced into the indented parts of
the corrugations, thereby limiting the movements of the spindle within regulated
distances, which correspond to the height of wick that will produce the light
required.
And my Invention consists, in the last place, in arrangements or means for
improving a light without the aid of a chimney to produce artificial draft. This
is accomplished by placing over the flame a cone or deflector, or two concs or
deflectors (the inner one of which may be round), made similar to those used in
lamps for burning mineral oils, but made of an oval or oblong form in horizontal
section, the slot for the flame to pass through being cut transversely to the long
axis of the cone.
The said cones or deflectors are made of the shape above stated in order to cause
a stronger current of air to impinge on the sides of the flame than on the ends
.thereof, for the purpose of spreading the flame and improving the combustion. A
similar result is accomplished by fixing on to any cone or deflector a circular band
of metal, which I call a radiator, fixed with its axis horizontal and transversely to
the flame, the ends of the said band being united to the cone or deflector just
below the end of the slot through which the flame issues. In the top part of the
band, or that immediately over the flame, is formed an aperture for the products of
combustion to pass through.
In some cases radiators are formed of two metal discs or plates fixed vertically
on the cone, one on each side of the long axis of the flame and parallel thereto, the
said plates having holes in the centre for the light to pass through.