IMPROVEMENTS IN SAFETY LAMPS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said William Jenkins and David
Morgan at the Office of the Commissioners of Patents on the 27th June
1882.
WILLIAM JENKINS and DAVID MORGAN both of Treorky in the County of
Glamorgan "IMPROVEMENTS IN SAFETY LAMPS"
Our invention relates to Safoty lamps and is applicable chiefly to those of the
Davy and Clanny type and our said Invention consists in forming a tube of tin
plate, copper or other suitable material, and covering or inserting in the top of the
same a cap of iron or copper wire gauze. This tube is of a diameter suited to
the lamp to which it is to be applied, it being inserted or made to fit into the top
part of the ordinary lower gauze of a Davy lamp and its being of such a length as
to reach from the top of the gauze so as to lap just below the ordinary shield of
such lamp, or of such length as to form in itself a shield, or a similar tubo without
a top of gauze is inserted or fitted into the lower gauze of a Clanny lamp, the said
tube being secured in each case to the lamp. Air spaces are formed in the ring
immediately below the glass of a Clanny lamp, and the plate or ring upon which
the glass rests is grooved so that only sufficient air can be admitted to the flame of
the lamp to support combustion. The said air spaces are covered with wire gauze.
By these improvements the Davy lamp is rendered a much safer lamp than it is
at present when used in an explosive mixture of gas and air. We also render the
Clanny lamp an absolutely safe lamp being immediately extinguished in an
explosive mixture. Both lamps are not in any way rendered less serviceable or
practicable in ordinary use by our improvements, at the same time they are rendered
infinitely more secure against explosion, should an explosive mixture of Gas and air
come upon them.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Jenkins and David Morgan in the Great Seal Patent Office
on the 27th December 1882.
WILLIAM JENKINS and DAVID MORGAN both of Treorky in the County of
Glamorgan IMPROVEMENTS IN SAFETY LAMPS"
"
Our said Invention relating to Improvements in Safety Lamps for mines is
applicable more particularly to what are known as the "Davy" and the "Clanny'
lamps, but is also applicable to other lamps of a similar character and consists in
fitting to such lamps a tube of tin or copper plate or other suitable material and
when applied to a Davy lamp covering or inserting in the top of the said tube a
cnp of wire gauze This tube is inserted into the ordinary lower gauze of a Davy
lamp and is of such a length as to reach from a short distance below the top of the
gauze to the bottom thereof so as to form of itself a shield, or so as to lap just
below the ordinary shield of such lamp if such shield be used.
In the said tube a space is cut for the light to pass through and for the
admission of the requisite quantity of air to maintain combustion at the burner.
In applying our Invention to lamps of the Clanny type a similar tube to that
herein before described but which may be without a top or cap of gauze is inserted
or fitted into the lower gauze of the lamp and air apertures or passages are formed
in a suitable part therein to admit only sufficient air to support combustion. These
openings may be conveniently in the ring situated below the glass of the lamp and
communicate with a space provided between the annular plate or ring upon which
the glass rests and the top surface of the oil reservoir the said air passages or
apertures being covered with wire gauze
And in order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures
Figure 1 of the accompanying drawings represents in sectional elevation a Davy
lamp fitted with our improvements Figures 2 and 3 represent respectively a
sectional elevation and a horizontal section (taken along the line 1-2 Figure 2) of
a lamp of the Clanny type illustrating the application of our invention thereto
Figure 4 is a similar view to figure 2 representing a slight modification and
Figure 5 is a detail illustrating a further modification
Referring to Figure 1 A is the oil reservoir of an ordinary Davy Lamp screwed
and locked in the lower ring B of the lamp in the usual manner The burner C
is surrounded by the wire guaze D over the upper end of which depends the outer
cylinder or cap E secured to the top ring F as usual According to our Invention
we fit inside the gauze cylinder D a cylinder G of tin copper or other suitable
material secured in position by a screwed ring H nipping its lower end between
the said ring H and the flange a formed in the ring B The tube extends upward
to within a short distance of the top of the gauze cylinder D and is provided at
the top with a wire gauze cap or cover I A portion of the side of the tube is cut
away or formed with an opening as at K through which the light from the lamp
passes and through which air to support combustion is admitted to the burner
but not in quantity sufficient to cause an explosion on the exterior of the lamp
should an explosive mixture be present in dangerous quantity. The tube G thus
forms a shield to the lamp and may if desired also be made a reflector by
polishing the interior surface thereof in order to increase the light giving power of
the lamp In applying the tube G to the Clanny lamp or to other similar lamps

page_text: in which the light passes through glass as shown at L in Figure 2 the opening K
in the tube G is dispensed with and air may be admitted to the burner Ċ to
support combustion through long slots, M formed in the lower ring B communicating
with a space N between the top surface of the oil reservoir A and the under side
of the annular plate or ring B which supports the glass L-The long slots M are
covered with wire gauze c over which may be placed a loose or adjustable ring d
provided with long slots e corresponding in size and shape to the holes or air
passages M in the ring B By turning the ring & over the ring B the size of the
apertures M may be varied and consequently the admission of air to the burner
regulated as required Owing to the length of the slots the gauze can be readily
cleaned from any material which may clog the interstices Marks may be made on
the outer casing to indicate when the passages are opened or closed The ring d
may however be fixed or it may be dispensed with or instead of admitting air
to the burner through the ring B openings may be made in the lower end of the
tube G extending nearly all round the tuble as shown at Min Figure 4 or a larger
number of openings or perforations may be made in the lower end of the tube as
shown at M, in the detail view Figure 5. These openings are covered with wire
gauze which may consist of a cylindrical lining to the tube G The cap or
cover I hereinbefore described with reference to Figure 1 is not considered
necessary with the lamp last described but may be used therewith if desired It
will be evident that if desired the wire gauze need not extend over the unperforated
part of the tube G.
By the improvements hereinbefore described the Davy lamp is rendered much
safer than it is at present when used in an explosive mixture of gas and air and
the Clanny lamp is rendered safe as it is almost immediately extinguished when
exposed to an explosive mixture whilst the said improvements do not in any way
render the lamps less serviceable in ordinary use.
Having now described and particularly ascertained the nature of our said
Invention and the manner in which the same is or may be used or carried into
effect we would observe in conclusion that what we consider to be novel and
original and therefore claim as the Invention secured to us by the hereinbefore in
part recited Letters Patent is
First, In Safety lamps of the Davy type or other safety lamps of a similar kind
the employment of a tube arranged in the interior of the lower part of the ordinary
wire gauze of the said lamps such tube being provided at the top with a cap or
cover of wire gauze substantially as described with reference to Figure 1 of our
drawings.
Second, In safety lamps of the Clanny type or other safety lamps of a similar
kind the employment of a tube arranged in the interior of the lower part of the
wire gauze in combination with passages or apertures above or below the glass or
at other suitable part for the admission of only sufficient air to the burner to
support combustion substantially as hereinbefore described and illustrated by our
Drawings.
In witness whereof wo the said William Jenkins and David Morgan have