IMPROVEMENTS IN APPARATUS FOR LIGHTING AND EXTINGUISHING STREET AND OTHER LAMPS
Year: 1874

page_text: LETTERS PATENT to Alfred Munford, of South Petherton, in the
County of Somerset, Lessee of Gas Works, for the Invention of
65
IMPROVEMENTS IN APPARATUS FOR LIGHTING AND EXTINGUISHING STREET
AND OTHER LAMPS."
Sealed the 26th February 1875, and dated the 22nd December 1874.
PROVISIONAL SPECIFICATION left by the said Alfred Munford at the
Office of the Commissioners of Patents, with his Petition, on the
22nd December 1874.
I, ALFRED MUNFORD, of South Petherton, in the County of Somerset,
Lessee of Gas Works, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN APPARATUS FOR LIGHTING AND EXTINGUISHING STREET
'
14
AND OTHER LAMPS," to be as follows:—
: This Invention has for its object improvements in apparatus for
lighting and extinguishing street and other lamps.
In order that street lamps may be lighted and extinguished automati-

page_text: with each lamp a valve connected with a weighted diaphragm. The
diaphragm closes a chamber which is in connection with the gas supply.
The diaphragm is so weighted that the pressure which is kept in the
mains during the daytime is insufficient to lift it, but when the night
pressure is let on from the works the diaphragm for each lamp rises,
opens the valve, and allows gas to pass out from the diaphragm chamber
to the burner. As the gas issues from the burner it is ignited by means
of a minute flame, which is kept constantly burning in immediate
proximity to the main burner. This flame is supplied by means of a
tube of small bore opening directly into the diaphragm chamber. It is
protected from drafts of air by a wind guard, so that it may not be liable
to be accidentally extinguished.
The diaphragm chamber is arranged to screw on to the top of the gas
supply pipe, and the burner is mounted on the top of the diaphragm
chamber, so that if the apparatus should become deranged at any time
it is readily removed and replaced by another in working order, there
being no more difficulty in this operation than in changing the ordinary
burner nipples.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Munford in the Great Seal Patent Office on 2
the 21st June 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
MUNFORD, of South Petherton, in the County of Somerset, Lessee of
Gas Works, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of December, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alfred Munford, Her special license
that I, the said Alfred Munford, my executors, administrators, and a
assigns, or such others as. I, the said Alfred Munford, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,

page_text: within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS
FOR LIGHTING AND EXTINGUISHING STREET AND OTHER LAMPS," upon the con-
dition (amongst others) that I, the said Alfred Munford, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alfred Munford, do hereby declare
the nature of the said Juvention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention has for its object improvements in apparatus for
lighting and extinguishing street and other lamps.
In order that street lamps may be lighted and extinguished automati-
cally simply by varying the pressure in the main I employ in connection
with each lamp a valve connected with a weighted diaphragm. The
diaphragm closes a chamber which is in connection with the gas supply.
The diaphragm is so weighted that the pressure which is kept in the
mains during the daytime is insufficient to lift it, but when the night
pressure is let on from the works the diaphragm for each lamp rises,
opens the valve, and allows gas to pass out from the diaphragm chamber
to the burner. As the gas issues from the burner it is ignited by means
of a minute flame, which may be kept constantly burning in immediate
proximity to the main burner. This flame is supplied by means of a
tube of small bore opening directly into the diaphragm chamber. It is
protected from drafts of air by a wind guard, so that it may not be liable.
to be accidentally extinguished.
The diaphragm chamber is arranged to screw on to the top of the gas
supply pipe, and the burner is mounted on the top of the diaphragm
chamber, so that if the apparatus should become deranged at any time
it is readily removed and replaced by another in working order, there
being no more difficulty in this operation than in changing the ordinary
burner nipples.

page_text: Figure 1 is an elevation and Figure 2 is a vertical section of a street
or other lamp burner provided with automatic lighting and extinguishing
apparatus constructed according to my Invention.
a is a case made in two parts which are secured together by the screws
or rivets a¹. At a the case receives and is screwed on to the end of the
gas supply pipe; 6 is a thin leather or india-rubber diaphragm, which is
nipped securely by its edges between the parts of the case, and to the
central portion of the diaphragm a metal disc of suitable weight is
attached. The gas has at all times free admission to the chamber which
the diaphragm encloses. The space over the diaphragm is not closed
air-tight, a small perforation being formed in the side of the case. c is a
passage provided to conduct the gas to the burner; a regulating screw
at c² serves to regulate the size of the flame. The mouth of the passage c
within the gas chamber receives a valve d, which when resting in its
seat prevents the gas passing. The valve d is linked to the diaphragm b,
and the diaphragm is weighted, as already described. e is a passage
provided to supply the small lighting flame at e¹; e' is a screw for regu-
lating this flame; f is a wind guard. It consists of an inner tube
surrounding the flame closed at the bottom, but with holes in the side,
and outside this tube is a somewhat larger tube also with perforations in
the side, but arranged so as not to coincide with the perforations in the
inner tube. I prefer to serrate the upper edge of the outer tube in the
manner shown. g is a small valve which I employ to close the passage e
when the gas is on to its full pressure. A weight, as shewn, tends to
hold the valve away from its seat, but a hook connected with the
diaphragm lifts the weight when the pressure is sufficient. So long as
the gas pressure is insufficient to lift the weighted diaphragm 6 a minute
flame only burns at e¹. As the pressure is gradually increased this flame
becomes large enough to insure the ignition of the gas when it com-
mences to issue from the main burner, which takes place when the
pressure is sufficient to move the weighted diaphragm and the valve d.
The diaphragm is not however at once lifted to its full height, and it
tends to rise first on the side which is not encumbered with the con-

page_text: nection with the small valve 9, so that this valve will not be brought to
its seat, and so the flame at e¹ extinguished until sufficient time has
elapsed after the first lift of the valve d. Similarly when the supply of
gas to the main is reduced the pressure falls gradually and the valve g
will be removed from its seat whilst the pressure is still considerable and
some time before the valve d closes. The gas issuing at e' ignites and
burns with a flame, which gradually diminishes in size as the pressure
falls, and the valve d coming to its seat extinguishes the flame at the
ALFRED MUNFORD. (L.s.)