Improvements in Street Lamps.
Year: 1896

page_text: Date of Application, 7th Aug., 1896-Accepted, 24th Oct., 1896
COMPLETE SPECIFICATION.
Improvements in Street Lamps.
I, WILLIAM CHALMERS CLARKE, of No. 82 John Street of the City and County of
New York, State of New York, United States of America, Gentleman, do hereby
declare the nature of my invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
My invention relates to that class of street lamps in which the individual lamps
are not connected with a central gas supply but are each provided with a local supply
of fuel and the object of my improvements is to provide means whereby acetylene
gas, which as is well known is generated upon bringing water in contact with a
suitable metallic carbide, may be conveniently, safely and economically used as an
illuminant with such lamps.
In certain respects this gas is particularly well adapted for such a purpose since
it can be generated at or near the spot where it is to be used, thereby avoiding the
expense of laying and maintaining street mains, and can also be produced in such
limited quantities as may be required to supply a given lamp or burner for a pre-
determined number of hours. It gives also a light of great brilliance and luminosity
well adapted for lighting large spaces and far exceeding that of any liquid or gaseous
illuminant heretofore employed for street lighting.
Certain difficulties incident to the nature of the materials employed in generating
the gas and the manner of its use have, however, to be provided for. Thus it is
necessary that the water and carbide employed in producing it shall be brought
together in such manner that no material amount of gas shall escape during the
operation, and also that the gas shall not escape from the gas receiving chamber
which is necessarily connected with the generating chamber when the latter is opened
for the purpose of removing the debris of decomposition and introducing fresh
charges of material.
To the end of providing such a means and method for operating a street lamp.
that it may be charged and recharged and operated with convenience and without
loss of gas, I provide a post or support for the lamp having a hollow gas-tight
body, the interior of which serves as a vertically elongated gas receiving chamber,
provided with a floor or bottom below which the support extends so as to be set
in the ground or otherwise suitably secured. From near the lowest point of this
gas chamber a gas pipe, open at its lower end, runs up through the gas chamber
to the burner between which and the gas chamber is interposed a pressure regulator.
Outside of the lamp support and near the bottom thereof is a generating chamber.
of cylindrical shape which is arranged vertically and is provided at top and bottom
with removable caps. From a point at or near the top of the generating chamber
a pipe leads into the gas chamber which it enters at a point as near as may be to
the floor or bottom thereof.
In using the apparatus the cylindrical generating chamber is charged from the top,
the lower cap being in place, with a water-proof cartridge containing carbide of
calcium, which is preferably so made as to closely fit the chamber diametrically
and of such length as to leave sufficient space in the chamber to receive the water
required for decomposing the carbide. The upper cap of the chamber being placed
in position the cartridge is then crushed or opened by a device provided for the
purpose, and the water in the chamber enters the cartridge, whereupon the gas is
generated and passes into the gas chamber. The quantity of carbide contained in
the cartridge should be such that the amount of gas generated and the pressure
under which it is stored in the gas chamber will be only sufficient to operatively

page_text: supply the burner for a desired or predetermined number of hours, allowance being
made on the first charging for such excess of quantity as will remain in the chamber
after the pressure is exhausted, and the light is permitted to burn until extinguished
through failure of gas pressure at the end of the given time. Owing to the fact
that the vertical diameter of the gas chamber is much greater than its horizontal
diameter and that the gas is taken by the feed pipe from near the bottom thereof,
the residue of gas remaining in the chamber when the pressure is so far reduced
that enough gas to support the flame is no longer supplied will not escape and be
replaced by air, as would otherwise be the case, but, being lighter than air is trapped
and remains in the upper part of the gas chamber ready to be added to the next
charge of gas, whereby an important economy is effected. In order to recharge the
chamber with gas the cock of the lamp burner is closed, or care is taken to ignite the
gas at the burner as soon as sufficient pressure is generated, the caps of the generating
chamber or cylinder are removed and the spent cartridge is driven out through the
lower opening of the cylinder. The lower cap is then replaced, a fresh cartridge is
inserted in the cylinder, and the generation of the gas is effected in the same manner
as before. Owing to the great vertical extension of the gas chamber, which may be
assisted, if desired, by an outwardly closing check valve in the pipe leading from the
generating cylinder to the gas chamber, no escape of gas will occur when the cylinder
is opened for recharging, except such small amount as may be present in the cylinder
which may be disregarded.
The invention will be best understood by reference to the accompanying drawings
in which
Fig. 1 shows a vertical section of the device, Fig. 2 an elevation thereof
Fig. 3 an enlarged section of the generating cylinder and Fig. 4 a cross section of
the same.
The same letters of reference indicate corresponding parts throughout the
drawings.
A, indicates the lamp post or support, which is made hollow so as to form a gas-
tight chamber B, the vertical .diameter of which is much greater than its horizontal
diameter. From a point near the bottom or floor, C, of the chamber B, a gas pipe, D,
the lower end of which is open, extends up through the top of the chamber to the
lamp burner a. Below the burner, a, is placed a pressure regulator, b, which may be
of any usual or well known form.
Outside the lamp support, A, is placed the generating chamber or cylinder, E,
consisting of a cylinder of suitable material having its long axis vertical. The
cylinder, E, is provided at each end with removable.cap, e.elby which it may be
closed gas-tight. The upper cap e¹ is provided with. a cutting or crushing device, F,
which may form a part of the cap and which when the cap is in position projects into
the cylinder and as the cap is screwed into place is forced downward and into a
cartridge, H, placed therein. The lower cap may also, if desired, be provided with
projections, which, when the cartridge is forced against them by the action of the
device, F, will pierce the lower end of the cartridge. The cylinder, E, is connected,
near its upper end, with the gas chamber, B, "by a pipe, G, which enters the
chamber, B, near the floor or bottom thereof.
In using the device the upper cap, el, of the cylinder, E, is removed and a water
proof cartridge containing carbide of calcium is inserted therein and a quantity of
water sufficient to effect the decomposition of the carbide is poured into the cylinder
above the cartridge. Preferably the cartridge is made to fit the cylinder so closely
that the water cannot pass down to the lower end of the cylinder but will remain
above the cartridge until it is opened, and the cartridge is forced so far down in the
cylinder when placed therein that the space above it will be sufficient for the reception
of the requisite quantity of water. The cartridge may be made to fit the cylinder
either by being itself of such diameter as to fit closely therein or by being provided at
its upper edge with an outwardly projecting flange, h which will fit closely against
the walls of the chamber. If desired this flange may be made to extend so far upward
as to form a cup in which the water will be contained. The cap e' is then screwed on

page_text: and the crusher, F, is forced down and into the end of the cartridge, so that the water
can pass in and combine with the carbide. Since all of the water is above the cartridge
in the cylinder it will all enter the cartridge and come in contact with the carbide and
thus be effective in forming gas so that it is unnecessary to provide space in the
cylinder for more than enough water to effect the decomposition of the maximum
amount of carbide used, and there is practically no surplus of undecomposed water
which might become frozen in cold weather, as would be the case if the water were
admitted to the cartridge at other than its highest point. The gas developed passes
into the gas chamber, B, and up through the pipe, D, to the burner where it is
consumed as required. The cartridge employed should be charged with such a
quantity of carbide as will provide sufficient gas to run the burner for the number
of hours during which it is desired the lamp shall be operated in a single night. By
so doing the lamp requires attention but once in each twenty-four hours, the
operation of supplying the gas being performed at the time when it is desired that
the lamp shall be lighted and the gas being then ignited and permitted to burn until
the gas pressure.becomes so reduced that it will no longer support the flame which
goes out of itself and the operation is repeated from day to day. Regard must also be
had in proportioning the gas chamber to the pressure under which the gas is to be
stored so that it shall be sufficient to maintain the flame for the required time as
otherwise while the gas supply may be ample as far as quantity is concerned the
flame may be prematurely extinguished through lack of sufficient pressure. Owing
to the relatively great vertical elongation of the gas chamber, B, and to the fact that
the gas is taken to the burner from the bottom thereof, any residue of gas remaining
in the chamber after the pressure becomes so reduced as to no longer support the gas
flame will not escape from the chamber but will remain therein to be added to the
next following charge. In order to renew the charge of carbide both the upper and
lower caps e e' of the cylinder E are removed and the spent cartridge is driven out
through the lower opening of the cylinder. The fact that the interior of the cylinder
or generating chamber when the caps are removed is simply a vertical tube open at
both ends thus presenting an open passage, enables this to be easily done, even in case
of the freezing of any small quantity of surplus water in the cylinder in cold weather
and also enables any lime that may have escaped from the cartridge to be washed or
scraped from the walls of the chamber. After the spent cartridge is removed the
lower cap e is put in place and the cylinder is charged and the gas generated in the
same manner as in the first instance, the gas burner being closed before the generation
of gas is begun and being again opened and the gas ignited when the gas pressure is
re-established.
By means of my invention an isolated street lamp can be operated with a minimum
of attention and in a simple and economical manner. As the lamps require visiting
but once each day, one man with, a vehicle provided with the necessary supply of
cartridges and water can efficiently attend to the lighting of a village or town of
considerable size, advantages which will be readily apparent to those skilled in
the art.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. As a means of operating street lamps the combination with a hollow lamp support
forming a gas chamber and having a gas pipe leading from near the bottom of such
chamber to the lamp burner, of a cylindrical gas generating chamber located outside
of said gas chamber and having its long axis vertical, a pipe connecting the upper
part of said generating chamber with the lower part of said gas chamber, removable
caps for the upper and lower ends of said generating chamber, a cartridge, adapted
to closely fit the interior of said generating chamber and containing material
adapted upon contact with water to generate illuminating gas and means for
opening the upper end of such cartridge when contained in said chamber after
the latter is closed, substantially as and for the purposes set forth.

page_text: 2. In a street lamp the combination of a hollow lamp support forming a vertically
elongated gas chamber, a gas supply pipe extending from near the bottom of said
chamber to the lamp burner, and a generating chamber exterior to said gas chamber
and consisting of a tube provided at the ends with removable caps and presenting
when such caps are removed an open passage, substantially as and for the purposes
set forth.
3. In a street lamp the combination of a hollow lamp support forming a vertically
elongated gas chamber, a gas supply pipe within said chamber and extending from a
point near the bottom thereof to the burner of the lamp and a gas generating chamber
focated exterior to said gas chamber and operatively connected therewith, substantially
as and for the purposes set forth.
4. In a street lamp the combination of a hollow lamp support forming a vertically
-elongated gas chamber and a gas generating chamber operatively connected therewith
and consisting of a cylinder having removable caps at the ends thereof and presenting
when such caps are removed an open passage, substantially as and for the purposes
set forth.
5. In a street lamp the combination of a gas chamber, a burner supplied therefrom,
and a gas generating chamber operatively connected with such gas chamber and
consisting of a cylinder having removable end caps and presenting, when such
caps are removed an open tubular passage, substantially as and for the purposes
.set forth.
Dated this 6th day of August 1896.
H. D. FITZPATRICK,
70 Wellington Street, Glasgow, Agent.