IMPROVEMENTS IN THE CONSTRUCTION OF CARRIAGE LAMPS AND SIGNAL LAMPS
Year: 1878

page_text: LETTERS PATENT to Francis Edward Merry, of Pimlico, in the County of
Middlesex, Foreman, for the Invention of " IMPROVEMENTS IN THE CONSTRUCTION
OF CARRIAGE LAMPS AND SIGNAL LAMPS."
Sealed the 21st March 1879, and dated the 25th September 1878.
PROVISIONAL SPECIFICATION left by the said Francis Edward Merry at the
Office of the Commissioners of Patents on the 25th September 1878.
FRANCIS EDWARD MERRY, of Pimlico, in the County of Middlesex, Foreman.
"IMPROVEMENTS IN THE CONSTRUCTION OF CARRIAGE LAMPS AND SIGNAL
LAMPS."
This Invention relates, firstly, to that class of carriage lamps which is provided
with a pendant glass bowl for receiving the drippings of oil, and through which the
light is transmitted downwards, the object being to prevent an overflowing of the
oil and thereby to avoid the unsightly appearance produced by oil accumulating in
the glass bowl. I now propose to form the oil cup with its top edges inclining
inwards towards the sides of the wick holder, but so as to leave between the edges
and the wick holder a free space for the passage upwards of air to the sides of the
wick. The lips of the cup thus inclined inwards serve to prevent the oil from
overflowing either by capillary attraction or by the shaking to which the lamp may
be exposed during a journey.
Another advantage consequent on bending the lips inward is that while the supply
of oil is brought up within say half the depth of the wick holder, it will be so far
below the flame as to remain comparatively cool.
The Invention relates, secondly, to an improvement in signal lamps such as those
used at the head and tail of railway trains and on shipboard, the object being to
prevent their being extinguished as is now commonly the case by the sudden opening
of the door of the lamp. This extinguishing of the light occurs in lamps which are

page_text: supplied with air through the dome or deflector, which deflector fits close on to the
top of the air chamber. In order to remove the defect in lamps of this construction
I set the dome or deflector a little above the air chamber, so as to allow of the air
passing freely from the air chamber into the air space surrounding the dome. By
this means the rush of air caused by the sudden opening of the door of the lamp
will, instead of passing up to the flame, enter the air space surrounding the dome
and leave the flame little if at all affected by the opening of the door. The air
chamber I supply with air through openings in the upper part of the lamp case,
which air I conduct downwards to the chamber by means of vertical channels formed
by an inner lining at the sides of the lamp case.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Francis Edward Merry in the Great Seal Patent Office on the
25th March 1879.
FRANCIS EDWARD MERRY, of Pimlico, in the County of Middlesex, Foreman.
"IMPROVEMENTS IN THE CONSTRUCTION OF CARRIAGE LAMPS AND SIGNAL
LAMPS."
This Invention relates, firstly, to that class of carriage lamps which is provided
with a pendent glass bowl for receiving the drippings of oil, and through which the
light is transmitted downwards, the object being to prevent an overflow of the oil
and thereby to avoid the unsightly appearance produced by oil accumulating in the
glass bowl. I now propose to form the oil cup with its top edges inclining inwards
towards the sides of the wick holder, but so as to leave between the edges and the
wick holder a free space for the play of air to the sides of the wick.
In Sheet I. of the accompanying Drawings, Fig. 1 is a sectional elevation of so
much of a railway carriage lamp taken through the centre of the oil and air tubes.
as will serve to explain the first head of my Invention.
Fig. 2 is a vertical section of the lamp taken in the line 1, 2, of Fig. 1, and Fig. 3
is a sectional plan view of the same, the deflector shewn in the above Figures being
removed. In these Figures A is the oil cup carried by the oil tubes B, B, which are
pendent as usual from an elevated oil reservoir. This oil cup is made oval in plan
view, and the plane of its major axis is provided with vertical recesses, which form
guides for the reception of the wick holder. The upper edge of this cup is bent
inwards as at a, except at the parts where the recesses occur, these being left open
at top for the admission of the wick holder.
C, C, are the air tubes open at top to an air chamber as usual and connected at
bottom to a vessel D, which surrounds the oil cup and carries at its upper end the
air deflector E. F is the wick holder suspended in the oil cup by flanged projections,
which rest on the ends of the slot formed in the deflector for the passage upwards
of the flame and gases of combustion. Rising up from the bottom of the vessel D
are small pipes d, which are open at both ends and permit of the circulation of air
between the air pipes C and the glass bowl G, while at the same time they provide
for the accumulation of a certain amount of overflow oil within the vessel D and
the air pipes C, and prevent the choking of the air pipes C in case of an undue
overflow of oil by providing an escape for that oil into the glass bowl. This office
however of the pipes d will be rarely exercised. The bending in of the lips a of
the oil cup, as shewn in Figures 1 and 3, will serve to prevent the oil from over-
flowing either by capillary attraction or by the shaking to which the lamp may be
exposed during a journey.
Another advantage consequent on this form of oil cup is that while the supply of
oil is brought up within say half the depth of the wick holder, it will be so far
below the flame as with the aid of the air playing freely over it to remain compara-
tively cool.
The Invention relates, secondly, to an improvement in signal lamps such as those
used at the head and tail of railway trains and on shipboard, the object being to
prevent their being extinguished as is now commonly the case by the sudden
opening of the door of the lamp. This extinguishing of the light occurs in lamps
which are supplied with air through the dome which fits close on to the top of the
air chamber.
In order to remove the defect in lamps of this construction I arrange the dome as
shewn at Fig. 4, Sheet II., which is a central sectional elevation of a signal lamp.
H is the dome fitted with an internal deflector I, and set above the air chamber K,
so as to allow of air passing freely from the air space surrounding the dome, that is,
from the lamp case upwards through the base of the dome.

page_text: By this means the rush of air caused by the sudden opening of the door of the
lamp will instead of passing directly on to the flame take the course of the air
supplied from the air chamber K, and leave the flame little if at all affected by the
opening of the door. The air chamber, which overlies the oil cup and forms a cover
thereto, is supplied with air through openings in the upper part of the lamp case,
which air is conducted downwards to the chamber by means of vertical chambers L, L,
formed by an inner lining at the sides of the lamp case.
M is the door of the lamp carrying the bull's eye N, which is colored in the well-
known manner by means of sliding screens.
The dome H is fitted at its base with a central socket, which fits on to the wick
tube and thus serves to hold the suspended dome in place. The air from the
chamber K passes upwards to the deflector and to the dome, as indicated by the
arrows, and any rush of air into the lamp caused by the opening of the door M
will take the same course, and thus the extinguishing of the lamp will be
avoided.
Having now set forth the nature of my Invention of "Improvements in the
Construction of Carriage Lamps and Signal Lamps," and explained the manner of
carrying the same into effect, I wish it to be understood that under the above in
part recited Letters Patent I claim,―
First. The means above described for controlling the tendency of the oil to flow
over the oil cup into the glass bowl of the lamp.
Secondly. The means above described for neutralizing the effect of a sudden rush
of air into signal lamps.
In witness whereof, I, the said Francis Edward Merry, have hereunto set my
hand and seal, this Twenty-fourth day of March, in the year of our Lord
One thousand eight hundred and seventy-nine.
Th
MADDY
F. E, MERRY.