IMPROVEMENTS IN SAFETY LAMPS
Year: 1858

page_text: LETTERS PATENT to Alfred Sterry, of the Gorwydd Colliery, Swansea,
'for the Invention of "IMPROVEMENTS IN SAFETY LAMPS."
Sealed the 9th July 1858, and dated the 22nd January 1858.
PROVISIONAL SPECIFICATION left by the said Alfred Sterry at the
Office of the Commissioners of Patents, with his Petition, on the
22nd January 1858.
I, ALFRED STERRY, of the Gorwydd Colliery, Swansea, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN SAFETY LAMPS," to be as
follows:-
In
This Invention has for its object improvements in safety lamps. For these
purposes the wire gauze which surrounds or partly surrounds the flame is
made into a globular or spherical form, the upper part or chimney: above the
flame being of a cylindrical or other shape, as has heretofore been the case.
By arranging the lamp in this way, the light will be enabled to pass more
freely through the gauze in an upward and downward direction than when the
gauze which surrounds the flame is of a cylindrical or conical form.
place of supplying oil to the wick in the way heretofore practised, the oil is
forced up to the wick by a piston acted on by a spring or otherwise,. in such
manner as to cause the supply of oil to the wick to be in excess, so that it may
overflow as in "moderateur argand lamps," or in place thereof the oil vessel is
supplied on one side of the lamp, and in such manner as to rise considerably
above the wick, and there is a horizontal partition dividing the oil vessel into

page_text: two parts and placed slightly below the level of the wick. The partition has
a valve in it, by which the oil or any part thereof in the upper part of the oil
vessel may be allowed to flow into the lower compartment of the vessel when
the oil in the lower part of the vessel has been consumed to such an extent as
to render it desirable to fill up the lower compartment of the oil vessel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Sterry in the Great Seal Patent Office on the
22nd July 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
STERRY, of the Gorwydd Colliery, Swansea, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of January, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Alfred Sterry, Her special licence that I, the said Alfred
Sterry, my executors, administrators, and assigns, or such others as I,
the said Alfred Sterry,, 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, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN SAFETY. LAMPS," upon the condition (amongst others) that I, the said
Alfred Sterry, 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 Sterry, do hereby declare
the nature of the said Invention, 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 safety lamps. For these
purposes the wire gauze which surrounds or partly surrounds the flame is
made into a globular or spherical form, the upper part or chimney above the
flame being of a cylindrical or other shape, as has heretofore been the case.

page_text: Figure 1. shows a side view, and Figure 2 a section of a safety lamp having
the wire gauze which surrounds the flame made into a globular or spherical
form, and the upper part or chimney of a cylindrical shape. The globe and
chimney are constructed of four pieces of wire gauze a, a, shown separately at
Figures 3. Each of the pieces of wire gauze a, a, forms part of the chimney,
and also of the globe or sphere, and is formed with radial flanges a', a', to
facilitate the pieces being connected together, the pieces a being formed into
the requisite shape by means of dies from a sheet of wire gauze. The wire.
gauze which I prefer to employ is formed of galvanized or white metal wire,
which does not stop so much light as the iron wire gauze employed heretofore.
The sections.a, a, are connected together by means of four pieces of metal b, b,
each of the pieces.b is formed from sheet metal, which is first cut into the
shape shown at Figure 4, and is then formed by dies so as to fit the flanges on
the pieces a.
The flanges on the pieces a, a, are placed between the pieces b,
and the pieces 6 are rivetted together and so connect the pieces a, a. The
bottoms of the pieces b, b, form a tube, into which is rivetted the piece c,
Figure 2, the ends of the pieces of wire gauze a being between them,
which piece c screws on to the upper part of the case of the lamp. The top
of the pieces 6 also form a tube, into which is rivetted the piece d, Figure 2,
the top of the chimney of wire gauze being between them. On the piece d
there is a screw thread, on to which is screwed the piece e, which has attached
to it a cap of wire gauze, as shown at Figures 1 and 2, and between the
pieces d and e is placed a disc of wire gauze f, which can readily be replaced
when burnt away. By constructing the wire gauze which surrounds the flame
of a globular or spherical form, the light will be enabled to pass more freely
through the gauze in an upward and downward direction than when the gauze
which surrounds the flame is of a cylindrical or conical form. In place of
supplying oil to the wick in the way heretofore practised, the oil is forced up
to the wick by a piston acted on by a spring or otherwise, in such manner as
to cause the supply of oil to the wick to be in excess, so that it
may overflow
as in "modérateur argand lamps," and the internal construction of the lamp
shown at Figures 1 and 2 of the Drawing is similar to that of an ordinary
modérateur lamp. Or in place of this arrangement, the oil vessel is in some
cases applied on one side of the lamp, and in such manner as to rise con-
siderably above the wick, and there is a horizontal partition dividing the oil
vessel into two parts and placed slightly below the level of the wick. The
partition has a valve in it, by which the oil or any part thereof in the upper
part of the oil vessel may be allowed to flow into the lower compartment of the
vessel when the oil in the lower part of the vessel has been consumed to such

page_text: an extent as to render it desirable to fill up the lower compartment of the oil
vessel.
Figure 4* is a side view, and Figure 5 is a horizontal section of a lamp
having the oil vessel applied to one side of it; and Figure 6 is a vertical
section of the oil vessel. In this lamp for one of the wire gauze sections a
plate of metal a* is substituted, which is stamped to the required form, so that
the oil vessel may fit it closely, as is shown by the Drawing. The oil vessel of
the lamp is divided into two parts by the partition 6*. c* is a valve, by which
oil is, when required, allowed to pass from the space above the partition to that
below. In order to attach the oil vessel to the other portion of the lamp, a
screw union is employed, consisting of a nut d*, Figure 4*, which embraces
a flange at the bottom of the gauze frame. and screws on to the thread ex
formed on the oil vessel.
In witness whereof, I, the said Alfred Sterry, have hereunto set my
hand and seal, this Nineteenth day of July, in the year of our Lord
One thousand eight-hundred and fifty-eight.
1
Witness,
F. KNIGHT,
31, Torriano Terrace,
Kentish Town.
ALFRED STERRY. (L.S.)