IN MINERS' SAFETY LAMPS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said William Tate at the Office
of the Commissioners of Patents on the 5th January 1880.
WILLIAM TATE, of Blackwell, in the County of Derby, Engineer.
IN MINERS' SAFETY LAMPS."
"IMPROVEMENTS
My Invention relates to improvements in miners' safety lamps, and more
particularly to an improved method of automatically extinguishing the light of the
lamp when brought in contact with explosive gases, in combination with an
arrangement for extinguishing the light if the lamp is attempted to be opened, and
also an improved arrangement for the admission of air to the interior of the lamp,
and I attain these objects in the following manner, that is to say :-I construct the
body of the lamp in a manner somewhat similar to those in use, that is, having a
lamp with an ordinary wick for the consumption of oil or other suitable material,
and protected by a glass chamber; on the top of the glass chamber I fix a vessel or
receptacle provided with a suitable inlet, and of a strength sufficient to resist a
considerable internal pressure; at the bottom of this vessel I fix a fusible plug
calculated to melt at a given heat, and being directly over the wick of the lamp.
This vessel is supplied with carbonic acid gas under a pressure of, say, 5 to 10 lbs.
per square inch; a small pipe from the above described vessel communicates with
a valve fixed in a convenient position near the wick, the pressure in the vessel
keeping the valve closed. The underside of this valve is in connection with one
arm of a lever and spring or similar mechanical contrivance, which when the
valve is raised extinguishes the light. To admit the air to the lamp I make the
pillars or rods that connect the top and bottom parts of the lamp together of
tubing, the top ends being open to the atmosphere and the bottom ends open only
to the interior of the lamp, so that all the air to feed the lamp is taken from the
top of the lamp only.
The action of the lamp as follows:-
The lamp being lighted and the vessel being charged with carbonic acid gas

page_text: valve and keeps that also closed; on being brought in contact with inflammable
gas the flame of the lamp is enlarged, and the heat melting the fusible plug or
plate the carbonic acid gas escapes and extinguishes the light at the same time,
the pressure being removed from the lower valve the lever before mentioned comes
into operation and aids in extinguishing the light.
To prevent tampering with the light a simple arrangement such as an inclined
wedge is made, so that on turning the lamp partially round to open it the wedge
shall pass under and lift the lower valve, and thus open a passage for the carbonic
acid gas to enter the lamp.
It is obvious that from the foregoing description the lamp cannot be put together
lighted unless the vessel is previously charged under pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Tate in the Great Seal Patent Office on the 5th July
1880.
WILLIAM TATE, of Blackwell, in the County of Derby, Engineer. "IMPROVEMENTS
IN MINERS' SAFETY LAMPS."
The said Invention relates to improvements in "Miners' Safety Lamps," and
more particularly to a method of automatically extinguishing the flame of the
lamp when brought in contact with explosive gases, or from other causes, in com-
bination with a mechanical arrangement for extinguishing the light if the lamp is
opened, also improvements in the admission of air to the interior of the lamp, and
also to the construction of certain parts of the said lamp. And in order that the
said Invention may be more fully understood, I shall now proceed more particularly
to describe the same, and for that purpose shall refer to the several Figures on the
aunexed Sheet of Drawings, and to the letters and figures marked thereon. I
construct, for example, the body of the lamp in a manner somewhat similar to
those now in use, having an ordinary wick for the consumption of oil, or other
equivalent material, and protected by a glass chamber. The glass is supported on
a ring of peculiar construction, and is held screwed up against a corrugated metallic
ring placed between the top of the glass and a fixed collar in the frame of the
lamp; this upper ring being corrugated has sufficient elasticity to allow for the
expansion of the glass from the heat of the lamp.
I may mention that I am well aware that elastic packing and flat metallic plates
have been used for this purpose, but not a corrugated ring. At the top of the lamp
and over the position of the flame from the wick I fix a fusible plug or plate of a
material calculated to melt at a given amount of heat, the upper side of the plug
or plate being in connectien with a pipe or tube or opening leading into a vessel or
reservoir. This vessel or reservoir is by preference charged through a suitable
opening with carbonic acid gas (but other suitable fluids may be used) at a con-
siderable pressure; a second outlet from the vessel or reservoir to the interior of
the lamp is arranged below the glass ring, and is provided with an ordinary valve
which is kept closed by the pressure of the carbonic acid gas (or other similar
fluid). The valve spindle rests upon and holds down a short lever and spring, which
engages with a second lever or crank fixed upon the oil vessel, and attached to a
slide or extinguisher for the purpose of putting out the flame of the wick. I also
provide a short inclined plane attached to the oil vessel, and so arranged that if the
oil vessel is turned round after the lamp is charged the inclined plane or wedge
passes under the end of the beforementioned short lever and spring, and in forcing
it up raises the valve also, thus allowing an escape of the carbonic acid gas, which
being under pressure rushes out and extinguishes the flame; the action of the lever
also forces forward the slide or extinguisher over the wick. Should the miner trim
bis wick so that the flame was of a dangerous size it would melt the fusible plug
or plate, and the light would be extinguished; also, in the case of the presence of
inflamable gas the increased heat in the lamp would produce a similar result. I
do not bind myself to the details of mechanism, as, for instance, in one arrangement
of my Invention I place the reservoir for the carbonic acid or other gas or fluid on
the top of the lamp, but in the arrangement shown in the Drawings I place it near
the base; also, the lever motion connecting the valve and the extinguisher and the
method of attaching the oil lamp to the casing, may obviously be carried out in
different ways to attain the same object without departing from the spirit of my
Invention.
For the better admission of air, and so that there shall be no through draft, I
construct the lamp in the following manner :-I make an annular chamber near
the base of the lamp casing having a suitable opening or openings for the admission

page_text: of air on one side only, the side of the annular chamber opening to the lamp is
closed by the "glass ring;" this ring also forms a second annular chamber, the
side which closes the chamber in the casing being perforated to allow the air to
enter from the outer chamber. The bottom side of the glass ring is constructed of
wire gauze, through which the air passes into the body of the lamp. If the miner,
having extinguished his lamp in opening it, or from any other cause, relights it,
and attempts to put it together, the altered position of the short lever, no longer
held down by the valve, acts upon the extinguisher and puts out the flame.
Fig. 1 is a sectional elevation of one arrangement of a lamp constructed according
to my Invention. A is the handle; B is the perforated cover; C, one of the pillars
of the framework; D is a dome of wire gauze; E is a perforated metallic cap over
the combustion chamber; F is the corrugated elastic ring placed between the glass
G and the fixed collar H; I, the glass ring showing the wire gauze at J; K is the
first annular chamber running round the lamp casing, into which the air is admitted
on one side of the lamp only; L is the fusible plug or plate opening into the
pipe M, which communicates with the vessel or reservoir N; O is the valve holding
down the short lever P and the spring Q; R is the crank; S, the slide or
extinguisher; T, the wick and flame; V, the oil vessel.
Fig. 2 is an enlarged view of the corrugated elastic metallic ring.
Fig. 3 is an enlarged view of the glass ring, part being shown in section..
Fig. 4 is a view of the underside of the same.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
1st. Automatically extinguishing the flame of miners' lamps when such flame is
enlarged either wilfully or from the pressure of inflamable gas, or other causes, or
when the lamp is attempted to be opened by means of the admission of carbonic
acid gas, or other similar gases, substantially in the manner as described and
illustrated.
2nd. The method of admitting air through one or more openings on one side of
the lamp only, through an annular air chamber, into the glass ring, and from the
ring through a wire gauze on the underside, into the combustion chamber, substan-
tially as described and illustrated.
3rd. The use of a corrugated metallic ring in connection with the glass for the
prevention of breakage, substantially as described and illustrated.
4th. The construction of the glass ring with an annular air chamber having
inlets, and a wire gauze underneath, substantially as described and illustrated.
5th. The arrangements for the prevention of relighting the lamp, substantially
as described and illustrated.
In witness whereof, I, the said William Tate, have hereunto set my hand
and scal, this Third day of July, in the year of our Lord One, thousand
eight hundred and eighty.