IMPROVEMENTS IN LIGHT- ING RAILWAY CARRIAGES AND IN THE MECHANISM OR APPARATUS EMPLOYED THEREFOR, THE SAME BEING APPLICABLE FOR LIGHTING TRAMWAY CARS, SHIPS, FACTORIES, AND OTHER BUILDINGS
Year: 1876

page_text: LETTERS PATENT to David Laidlaw, of Glasgow, in the County of Lanark,
North Britain, Gas Engineer, for the Invention of "IMPROVEMENTS IN LIGHT-
ING RAILWAY CARRIAGES AND IN THE MECHANISM OR APPARATUS EMPLOYED
THEREFOR, THE SAME BEING APPLICABLE FOR LIGHTING TRAMWAY CARS, SHIPS,
FACTORIES, AND OTHER BUILDINGS."
Sealed the 23rd June 1876, and dated the 19th April 1876.
PROVISIONAL SPECIFICATION left by the said David Laidlaw at the Office
of the Commissioners of Patents on the 19th April 1876.
DAVID LAIDLAW, of Glasgow, in the County of Lanark, North Britain, Gas
Engineer. "IMPROVEMENTS IN LIGHTING RAILWAY CARRIAGES AND IN THE
MECHANISM OR APPARATUS EMPLOYED THEREFOR, THE SAME BEING APPLICABLE
FOR LIGHTING TRAMWAY CARS, SHIPS, FACTORIES, AND OTHER BUILDINGS."
This Invention, which relates to improvements in lighting and in the machinery
or apparatus employed therefor, is more especially adapted to the lighting of railway
carriages, but it may also be used for lighting tramway cars, steam and sailing
ships, factories, and other buildings.
The Invention essentially consists in an improvement in that class of apparatus
commonly known as "air-gas" apparatus, that is to say, in which atmospheric air
is converted into illuminating gas by passing it through a vessel or vessels containing
a volatile hydrocarbon, such as gasoline.
As applied to railway carriages the apparatus consists of one or more hollow
or conical mouthpieces in which as the train moves air is caught, and through
which it is carried into the air holder, which consists by preference of an elastic or
bellows-like reservoir, one or more of which reservoirs may be arranged beneath
the seats of the railway carriage, or a van containing one such reservoir of larger
capacity may be used. The conical mouthpieces are provided with a joint, so
that they may always be turned to face the direction in which the carriage or train
is to travel, and they are also provided with a valve at their inner end, which
closes when the carriage or train stops, and so shuts in the air. The reservoir is
acted upon by weights or springs so as to produce at all times a constant pressure
on the contained air, and thereby cause it to flow out therefrom into the carburetter
or carburetters in a constant steady stream. By means of the flexible reservoir
the shocks due to the shaking motion of the carriage are absorbed, and the pressure
of the weights or springs thereon causing the constant flow of air herein-before
referred to produces a steady flame at the burners through which the carburetted
A.J

page_text: air escapes from the carburetter. The carburetters may be arranged beneath
the seats of the railway carriages, or they may be placed in one or more of the
vans.
The same apparatus may be used for lighting steam or sailing ships, tramway
cars, factories, and other buildings, and in any case where power is conveniently
situated for driving the air-pumps.
In place of the flexible or bellows-like air holder herein-before described a
holder constructed after the manner of an ordinary gas holder with a water-tank
may be used.
In place of the air collecting conical mouthpieces one or more
pumps worked by a screw and tangent wheel from one or more of the axles of a
carriage van or train may be used.
In the case of conveying the gas from carriage to carriage in trains, the pipes
formning the gas connexion between the carriages are fitted with water lutes instead
of screw or analogous couplings, but when each carriage is fitted with apparatus for
collecting or forcing in the air, gas or air connexions between the carriages are
rendered unnecessary.
In case of any emergency by which a train is caused to stand, so that the
supply of air is not kept up, one or more hand pumps is or are fitted on the train,
by working which the supply is kept up until the train is restarted, or the
reservoirs may be large enough to hold a supply of air for any desired length of
time.
"
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David Laidlaw in the Great Seal Patent Office on the 13th October
1876.
DAVID LAIDLAW, 'of Glasgow, in the County of Lanark, North Britain, Gas
Engineer. "IMPROVEMETS IN LIGHTING RAILWAY CARRIAGES AND IN THE MECHANISM
OR APPARATUS EMPLOYED THEREFOR, THE SAME BEING APPLICABLE FOR LIGHTING
TRAMWAY CARS, SHIPS, FACTORIES, AND OTHER BUILDINGS."
My said Invention, which relates to improvements in lighting and in the
machinery or apparatus employed therefor, is more especially adapted to the
lighting of railway carriages, but it may also be used for lighting tramway cars,
steam and sailing ships, factories, and other buildings.
The Invention essentially consists in an improvement in that class of apparatus
commonly known as "air-gas" apparatus, that is to say, in which atmospheric air
is converted into illuminating gas by passing it through a vessel or vessels containing
a volatile hydrocarbon, such as gasoline.
And in order that my said Invention may be properly understood I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to
the annexed Sheet of Drawings, and to the letters and figures marked thereon,
that is to say :-
On the Sheet of Drawings hereunto appended Figure 1 is a side elevation, and
Figure 2 a vertical section of part of a railway carriage illustrating one method
under which the improvements in lighting constituting my said Invention may be
applied thereto. Figure 3 is a horizontal section of the same portion of the
railway carriage, parts of the apparatus employed in carrying out my said Invention
being illustrated thereon in plan.
As shewn by these Figures the apparatus consists of conical or bell-shaped mouth-
pieces A, in or by which, as the carriages constituting the train are drawn along,
atmospheric air is caught and through which it passes into an air holder B placed
below one of the seats in each carriage.
The mouthpieces A, which are connected to the holder B by pipes C, are each
also formed or provided with a joint on which they are capable of being turned

page_text: round so that their open parts shall at all times face the direction in which the
train is to proceed, and they are also provided with hanging or flap valves at the
position marked on the Drawings, or at other convenient position, which valves,
when the carriage or train stops, close against the inner ends of the mouthpieces A,
and so prevent the escape of air from the holder B through the said mouthpieces.
The holder B consists by preference of an elastic or bellows-like reservoir, which is
acted upon by weights or springs so as to produce at all times a constant pressure
on the contained air, and thereby cause it to flow out in a constant steady stream
from the holder B through the pipe D, by which it is conducted into the close
vessel or chamber E, preferably secured to the end of the carriage and at the outside
thereof. A volatile hydrocarbon liquid, such as gasoline, is contained in the close
vessel or chamber E, and the atmospheric air in its passage through the said
chamber coming in contact with the volatile hydrocarbon becomes carburetted and
converted into illuminating gas, which collects in the vessel E above the level of
the hydrocarbon liquid, and is from thence conducted by the pipe b to the burners
c in each compartment of the carriage, whereat it is ignited and consumed by means
of the flexible reservoir or holder B, the shocks due to the shaking motion of the
carriage are absorbed, and the pressure of the weights or springs thereon causing
the constant flow of air herein-before referred to produces a steady flame of the
carburetted air at the burners c.
To prevent the pressure of air within the air holder or reservoir from becoming
too great when the train is running at a high rate of speed, and thereby causing
carburetted air to issue from the burners c faster than it can be efficiently or
economically consumed, each holder or reservoir B is provided with one or more
safety valves e to relieve the pressure within the holders after the desired limit of
air pressure has been reached.
Instead of employing one air holder only on each carriage, as herein-before
described and shewn, two or more of such holders may be used and placed either
below the seats, below the flooring, on the roof, on the ends, or at other convenient
parts of the carriage, or in lieu of placing the air holder or holders on the carriages
themselves, such holders may be placed in one or more vans, in which case
communication between the carriages and the van or vans containing the holders is
effected by pipes connected by suitable couplings at the ends of the carriages.
Such connecting pipes, however, when a separate air holder to each carriage is used
are unnecessary.
Under any of these arrangements the capacity of the air holder or holders is
such as to permit of a constant and steady supply of air being sent through the
carburetters to the burners c during the time that the train is detained at a station
or at other ordinary times when its motion is stopped or retarded, such for example
as when a carriage is being uncoupled, or a train or part thereof being shunted.
Instead of placing the carburetter E in the position shewn on the Drawings, it
may be placed in any other convenient position outside the carriage, or it may be
situated under a seat, or at other part of the interior of the carriage, or as herein-
before described with reference to the air holders or reservoirs, one or more car-
buretters may be placed in a van or vans attached to the train, the carburetted'
air being conducted to the burners through pipes coupled at the ends of the
carriages.
On each carburetter a filling cock f is provided for introducing the gasoline or
hydrocarbon liquid, and an overflow plug or cock is also provided at the position
marked g for the purpose of maintaining the liquid at a fixed level.
Figure 4 of the Drawings hereunto appended is a longitudinal section of a
railway carriage illustrating another method under which the improvements in
ighting constituting my said Invention may be applied thereto. As shewn by the
said Figure the apparatus consists of an air-pump A bolted to the floor or framing
of the carriage, and whose piston or plunger B is connected by the rod or link C
o a disc crank D, fixed on the upper end of a vertical shaft E, which is supported in
earings a, b, in a bracket or frame F bolted to the frame of the carriage. On the

page_text: lower end of the shaft E a worm wheel G is fixed and geared with a tangent screw
H secured on one of the axles I of the carriage. At the suction and delivery end
of the pump A a valve chest or chamber J is placed, and from the said chest or
chamber one branch c leads into the pump whilst another branch & communicates
with an elastic or bellows-like reservoir K placed beneath one of the seats of the
carriage. Suitable valves are placed in these branches. A branch or connecting pipe
Z communicates between the reservoir K and the chamber or vessel L which
constitutes the carburetter, and is similarly placed beneath another or the same seat
in the carriage. From the upper end of the carburetter L a pipe leads to the
burner fin each compartment or part of the carriage, as shewn on the Drawings.
By means of the pump A, driven as hercin-before described, a current of air under
pressure is forced into the elastic or bellows-like reservoir, which being acted upon
by weights or springs as herein-before set forth produces at all times a constant
pressure and steady flame at the burners f
In place of the flexible bellows-like reservoir K for containing the air a
holder constructed after the manner of an ordinary gas holder with a water-tank
may be employed with either of the arrangements herein-before described,
and instead of placing one reservoir only on each carriage, as shewn at Figure
4, two or more of such reservoirs constructed under either of the modes set
forth may provided, together with a like number of air-pumps, carburetters, and
other apparatus in connexion with the reservoirs.
The apparatus now under reference is also capable of being further modified in
manner similar to that described with reference to the arrangement illustrated by
Figures 1, 2, and 3 of the Drawings, that is to say, instead of placing the apparatus
on each carriage throughout the train it may be situated in one or more vans and
the carburetted air conducted therefrom to the burners through pipes connected at
the ends of the carriages. When the air holders and carburetters are placed in a
van or vans the pipes forming the gas connections between the several vehicles are
preferably fitted with water lutes instead of screw or analogous couplings, so that they
may be uncoupled with the maximum of facility.
Under another arrangement of the apparatus, shewn at Figure 4, the air reservoirs
and pumps only may be placed on one or more vans and the carburetters on the
carriages, these being situated either under the seats, under the flooring, on the
carriage ends, or at other convenient part.
To provide for any emergency by which a train is caused to stand for a length of
time, and the supply of air is thereby not kept up with the arrangement illustrated at
Figure 4, or with modifications thereof, one or more hand pumps is or are fitted on
the train, for example in the guard's van, by working which the quantity of air
requisite to illuminate the several vehicles (when carburetted as herein-before set"
forth) is maintained until the train is restarted, or each carriage may be provided
with a supplementary reservoir which would keep up the supply on such occasions
or maintain the supply when in disconnecting carriages the communication with
the reservoirs in the van or vans is broken.
The improvements in lighting constituting my said Invention besides being
employed in lighting railway trains under any of the modes herein-before described,
may also be used for lighting tramway cars, steam or sailing ships, factories and
other buildings, and in other situations where a current of air may be obtained, as
set forth with reference to Figures 1, 2, and 3 of the Drawings, or where power may
conveniently be had for driving the air-pumps, it being explained that I do not
restrict myself to the method herein-before described and shewn at Figure 4 of
the Drawings of pumping the air for conversion into illuminating gas, as other
arrangements of pumping apparatus operated by steam or other power are in some
cases equally or more applicable for that purpose.
Having now described and particularly ascertained the nature of my said
Invention, and several systems or modes in or under which the same is or may be
used or carried into practical effect, I desire to observe in conclusion that I am
aware that the process of carburetting air by means of a volatile hydrocarbon

page_text: which I use is not novel, and I therefore make no claim thereto, but what I do
consider to be novel and original, and therefore claim as constituting the Invention
secured to me by the herein-before in part recited Letters Patent is-
First. The general arrangement and combination of mechanism constituting the
improved lighting apparatus herein-before described and shewn at Figures 1, 2,
and 3 of the Drawings, or any mere modification thereof, and particularly the
part or parts thereof, namely, the mouthpieces A and their connexions by which
air is caught and forced into the reservoir and carburetters by the motion of the
train, and the employment of the same in lighting railway carriages, tramway cars,
steam and sailing ships, substantially as set forth.
Second. The general arrangement and construction of mechanism constituting
the improved lighting apparatus herein-before described and shewn at Figure 4 of
the Drawings, or any mere modification thereof, and the employment of the same in
lighting railway trains, tramway cars, steam and sailing ships, factories and other
buildings, substantially as set forth.
Third. The arrangement and construction of mechanism herein-before described
and shewn at Figure 4 of the Drawings for driving the air-pump from the axle of a
railway carriage or van, or any mere modification of such mechanism by which the
speed of the pump piston is reduced to that at which it will pump air with a
minimum loss of effect.
Fourth. The arrangement of the air reservoirs beneath the seats of railway
carriages or in one or more vans, substantially as herein-before described and in
part shewn on the accompanying Drawings.
Fifth. The arrangement of the carburetters on the ends of railway carriages or
beneath the seats or at other convenient parts thereof, or in one or more vans,
substantially as and for the purpose set forth and in part illustrated on the Drawings
hereunto annexed.
In witness whereof, I, the said David Laidlaw, have hereunto set my hand
and seal, this Eleventh day of October One thousand eight hundred and
seventy-six.
DAVID LAIDLAW. (L.S.)