IMPROVEMENTS IN THE CONSTRUCTION OF MINERS' SAFETY LAMPS
Year: 1876

page_text: LETTERS PATENT to Edward Vincent Gardner and John Harcourt Gardner,
both of Berners Street, Oxford Street, in the County of Middlesex, for the
Invention of " IMPROVEMENTS IN THE CONSTRUCTION OF MINERS' SAFETY
LAMPS."
Sealed the 12th January 1877, and dated the 17th July 1876.
PROVISIONAL SPECIFICATION left by the said Edward Vincent Gardner and
John Harcourt Gardner at the Office of the Commissioners of Patents on the
17th July 1876.
EDWARD VINCENT GARDNER and JOHN HARCOURT GARDNER, both of Berners
Street, Oxford Street, in the County of Middlesex. "IMPROVEMENTS IN THE
CONSTRUCTION OF MINERS' SAFETY LAMPS."
This Invention relates to certain improvements in the construction of safety
lamps for the use of miners, and whereby a greater amount of illuminating power,
combined with a less liability to accident from explosion is attained, than by any of
the safety lamps previously invented and in use.
This Invention embraces two primary modifications of construction and arrange-
ment, although the same principles may be applied respectively to other
arrangements.
In one of such modifications the construction and arrangement of the lamp is as.
follows: The lower portion of the lamp and exterior cylinder is formed of metal or
of any other suitable material, and is perforated to admit currents of air, and these
perforations are protected within and without this exterior cylinder by wire gauze.
The air from without passes through the wire gauze and the perforations through
suitable air ways or passages to the lower chamber of the lamp. The atmospheric
air admitted in this manner through the gauze and perforated metal cylinder to the.
lower chamber is free to circulate through the lamp and lamp burner. The top of
this chamber forms the oil container of the lamp, and the lamp is concentric to the
outer perforated cylinder, so that there are air ways existing between them, which
air ways lead to the lower chamber. The lamp is made so that the burner of any
convenient form admits the supply of air to the flame on its inner and outer

page_text: . surfaces, and thus fully oxidizes the fuel, and obtains a larger and purer flame; a
suitable glass chimney, if needed, is placed over the flame, the saine being so
fastened that it cannot fall off. A glass cylinder protected by suitable guards is
mounted on the lower portion or stand of the lamp in any convenient way. The
glass cylinder extends to a reservoir which forms the upper and inner portion of
the lamp, and is supported by suitable pillars and supports connected with the
lower part or stand of the lamp in a way to be hereafter more fully described. The
upper reservoir and oil container is of a double cylindrical form, that is to say, it
has a tube or channel through the centre thereof for the passage of the products of
combustion, and the exit of which is allowed through the cap or cover of the lamp.
This cover of the lamp is provided with a transverse passage or channel to allow
the products of combustion to pass through the exterior wire gauze casing and
cover. The upper reservoir contains the oil which is supplied to the lamp and
burner automatically. It has descending from the bottom thereof two or more
vertical tubes, which dip into the before-mentioned lower reservoir (or lamp and
burner) to a certain distance, and through which the oil descends into the latter.
The lower reservoir being closed at the top entirely, or with a valve, a pressure is
exerted upon the oil contained therein by that which descends from the upper
reservoir, and a portion of the oil is conveyed by suitable appliances to the wick.
The means of combustion and the production of illuminating power is thereby
obtained.
A modification of this Invention consists in placing the reservoir or receptacle for
the oil entirely at the bottom of the lamp, the same being surrounded by concentric
metal outer and perforated cylindrical casings of wire gauze, through which the
external atmospheric air is admitted. The apertures provided at the lower part of
the stand of the lamp being protected by wire gauze the air is free to pass to the
lower air chamber through the burner or burners, and through the wire gauze
casings of the apparatus. Currents of air are admitted through a tube or tubes or
channel or channels provided in the centre of the oil reservoir for the supply of the
necessary means of combustion to the wick. The wick is supported by suitable
supports or holders, and is surrounded by a glass chimney, if required, the whole
being protected by a wire gauze cylinder or cylinders in the usual way.
the oil reservoir is sometimes placed a glass cylinder protected by suitable wire or
other guards, and on which is mounted the wire gauze cylinder or cylinders forming
the upper part of the lamp. The whole is surmounted by a metallic cap in the
usual way to admit of the convenient escape of the products of combustion.
Above
In both the modifications of construction before described the wick or wicks
employed may be of any convenient form, similar to those used in ordinary lamps,
air being admitted both to the exterior and interior portions of the wicks, and any
description of oil, including mineral oil, may be used; the employment of such
wicks and of such oils being rendered possible by the before described arrangements
for the supply of atmospheric air for the purposes of combustion.
Safety lamps constructed as before described possess very important advantages
as compared with those hitherto known and used, inasmuch as they have far
greater illuminating power, and are not subject to the elements of danger which
arise so frequently in connection with the "Davy" lamp.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Vincent Gardner and John Harcourt Gardner in the Great
Seal Patent Office on the 17th January 1877.
EDWARD VINCENT GARDNER and JOHN HARCOURT GARDNER, both of Bernere 5
Street, Oxford Street, in the County of Middlesex.
CONSTRUCTION OF MINERS' SAFETY LAMPS."
"IMPROVEMENTS IN THE

page_text: Our said Invention relates to certain improvements in the construction of safety
lamps for the use of miners, and whereby a greater amount of illuminating power,
combined with a less liability to accident from explosion, is attained than by any of
the safety lamps previously invented and in use.
Our said Invention embraces two primary modifications of construction and
arrangement, although the same principles may be applied respectively to other
arrangements.
In one of such modifications the construction and arrangement of the lamp is as
follows: The lower portion and exterior cylinder of the lamp is formed of metal,
or of any other suitable material, and is perforated to admit currents of air; and
these perforations are protected within and without the said exterior cylinder by
wire gauze.
The air from without passes through the wire gauze and the
perforations, through suitable air ways or passages to the lower chamber of the
lamp. Sometimes we employ only a perforated metal cylinder or cylinders without
wire gauze, and sometimes the wire gauze cylinder exterior to the lamp case is
dispensed with. The perforations in the lamp case may be placed in any or in the
most convenient position, but generally we make them on the top or on the sides of
the metal cylinder. The atmospheric air admitted in this manner through the
gauze and perforated metal cylinder to the lower chamber is free to circulate
through the lamp and lamp burner or burners. The top of this chamber forms the
oil container of the lamp, and the lamp is concentric to the outer perforated
cylinder, so that there are air ways existing between them, which air ways lead to
the lower chamber. The lamp is made so that the burner, which may be of any
convenient form, admits the supply of air to the flame or flames on the inner and
outer surfaces, and thus fully oxidises the fuel and obtains a larger and purer flame
or flames.
A suitable glass chimney, if needed, is placed over the flame, the same
being so fastened that it cannot fall off. A glass cylinder protected by suitable
guards is mounted on the lower portion or stand of the lamp in any convenient
way. The glass cylinder extends to a reservoir which forms the upper and inner
portion of the lamp, and is supported by suitable pillars and supports connected
with the lower part or stand of the lamp in a way to be hereafter more fully
described. The upper reservoir and oil container is of a double cylindrical form,
that is to say, it has a tube or channel through the centre thereof for the passage of
the products of combustion, and the exit of which is allowed through the cap or
cover of the lamp. This cover of the lamp is provided with a transverse passage
or channel to allow the products of combustion to pass through the exterior wire
gauze casing and cover. The upper reservoir contains the oil which is supplied to
the lamp burner automatically. It has descending from the bottom thereof two or
more vertical tubes, which dip into the before-mentioned lower reservoir or lamp
and burner to a certain distance, and through one of which the oil descends into the
latter. The lower reservoir being closed at the top entirely except where the wick
passes, or with a valve, a pressure is exerted upon the oil contained therein by that
which descends from the upper reservoir, and a portion of the oil is conveyed by
suitable appliances to the wick; one of the said two tubes from the upper vessel or
reservoir of oil is for the purpose of feeding the lower vessel or lamp with the fuel,
and the other of such tubes is for equalizing the pressure of the air. Thus, the one
which supplies fuel commences at the lower part of the upper vessel, and continues
down and into the lower one or lamp to a proper distance, so as to keep the lamp
fed on the principle of a bird fountain; the other tube commences in the upper part
of the upper vessel or reservoir above the surface of the oil, and continues
downwards to the top of the lower vessel or lamp above the oil which is in the
same, so that in the event of undue pressure in the reservoir above the air can
find its equilibrium without flooding the lamp flame or flames below. The means
of combustion and the production of illuminating power are thereby obtained.
A modification of this Invention consists in placing the reservoir or receptacle
for the oil entirely at the bottom of the lamp, the same being surrounded by the
concentric metal outer and perforated cylinder, with or without the before-mentioned

page_text: cylindrical casings of wire gauze, through which the external atmospheric air is
adınitted. The apertures are so provided at the lower part of the stand of the lamp
that the air is free to pass to the lower air chamber through the burner or burners,
and through the wire gauze casings of the apparatus, when employed, currents of
air are admitted through a tube or tubes, or channel or channels, provided in the
centre of the oil reservoir for the supply of the necessary means of combustion to
the wick or wicks. The wick or wicks is or are supported by suitable supports or
holders, and is or are surrounded by a glass chimney, if required, the whole being]
protected by a wire gauze cylinder or cylinders in the usual way. Above the oil
reservoir is sometimes placed a glass cylinder protected by suitable wire or other
guards, and on which is mounted the wire gauze cylinder or cylinders forming the
upper part of the lamp. The whole is surmounted by a metallic cap in the usual
way to admit of the convenient escape of the products of combustion.
We
In both the modifications of construction before described the wick or wicks
employed may be of any convenient form or material, such as asbestos or wire, or
similar to those used in ordinary lamps; air is admitted to each side or to the
exterior and interior portions of the wicks or wick, and any description of oil,
including mineral oil may be used, or mixtures of mineral and vegetable oils.
prefer, however, to employ a mixture of camphor and mineral and vegetable oils,
as for example, equal parts of colza oil and paraffine or petroleum oil, in which has
been dissolved a suitable proportion of camphor, so as to produce a solid white flame
without smoke. The use of the said wicks or wick, and of such oils or mixtures
is rendered possible by the before described arrangements for the supply of
atmospheric air for the purposes of combustion; we do not, however, claim or
consider the employment of such oils or mixtures as forming any part of or as being
included in our said Invention.
Safety lamps constructed and furnished as before described possess very im-
portant advantages as compared with those hitherto known and used, inasmuch as
they have far greater illuminating power, and are not subject to the elements of
danger which arise so frequently in connection with the Davy and other safety
lamps.
Having thus declared and ascertained the nature of our said Invention, and in
what manner the same is to be performed, we would observe in conclusion that
what we consider novel and original, and therefore claim as constituting the
Invention secured to us by the said herein-before in part recited Letters Patent
are, the improvements in the construction of miners' safety lamps, substantially as
herein-before set forth and described, or any mere modifications thereof.
In witness whereof, I, the said John Harcourt Gardner, on behalf of myself
and the said Edward Vincent Gardner, have hereunto set my hand and seal,
this Seventeenth day of January, in the year of our Lord One thousand
cight hundred and seventy-seven.
JOHN HARCOURT GARDNER. (L.s.)