IMPROVEMENTS IN SAFETY LAMPS FOR MINERS
Year: 1868

page_text: LETTERS PATENT to Henri Adrien Bonneville, of the British and
Foreign Patent Offices, 18, Chaussée d'Antin, Paris, in the Empire
of France, and 10, Sackville Street, Piccadilly, in the County of
Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
SAFETY LAMPS FOR MINERS." -A communication from Richard
Werdermann, residing at Dortmund, in the Kingdom of Prussia,
Engineer.
Scaled the 1st January 1869, and dated the 20th October 1868.
COMPLETE SPECIFICATION filed by the said Henry Adrien Bonneville
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 20th October 1868, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRI
ADRIEN BONNEVILLE, of the British and Foreign Patent Offices,
18, Chaussée d'Antin, Paris, in the Empire of France, and 10, Sackville
Street, Piccadilly, in the County of Middlesex, Patent Agent, send
greeting.

page_text: WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
SAFETY LAMPS FOR MINERS," a communication from Richard Werdermann,
a person resident at Dortmund, in the Kingdom of Prussia, Engineer,
and have petitioned Her Majesty to grant unto me, my executors,
administrators, and assigns, Her Royal Letters Patent for the same,
and made solemn declaration that it is a communication.
NOW KNOW YE, that I, the said Henri Adrien Bonneville, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the Invention, and the
manner in which the same is to be performed, reference being had to
the accompanying Drawings, and to the figures and letters marked
thereon, that is to say:-
The improvements communicated to me relate, firstly, to the auto-
matical extinguishing of miners' safety lamps in the first place when
the accumulation of gases inside the lamp by penetrating the wire
gauze increases the intensity of the flame and caloric so as to heat the
wire gauze red hot or bring about its rupture and thus cause the ignition
of the gases outside, or when the miner attempts to open the lamp;
secondly, to obviate against the danger resulting in the rupture or
deterioration of the wire gauze when it presents a large surface.
These improvements are represented in the accompanying Drawings,
Fig. 1 of which is a vertical section of a lamp constructed with the
ordinary chimney in wire gauze; Fig. 2 is à plan view of the lower
portion of the lamp; and Fig. 3 a vertical section of the upper portion
modified.
The lamp is constructed well nigh in its integrity after the manner
of the ordinary safety lamp, with the oil reservoir a, the wick holder b,
the rod with hooks c to snuff and raise the wick, the top with suspensive
ring d connected by means of metal rods e to the ferrule which screws
on to the oil reservoir.
The first part of these improvements consists in constructing the
cylinder or chimney of the lamp in two parts, the lower one g of thick
crystal so as to have the full benefit of the flame, the other / of wire
gauze. At the upper and inside part of this wire gauze chimney to an
iron rod i a sheet-iron calotte or cap m is held suspended by means of a
pin made of some metal fusible at about 300 or 350 degrees running
through the rod i; when the gases penetrate the wire gauze in too great a

page_text: quantity, feeding the combustion beyond measure, and increasing the
temperature, this pin melts and lets the cap m fall, sliding down between
iron rods n on a metal ring o placed above the crystal cylinder which
it protects, and extinguishes instantaneously the lamp by closing the
chimney, thus warning the miner that gases accumulate around him.
Another important part of these improvements represented, Fig. 3,
consists in constructing the upper portion of the chimney in sheet iron
or tin plate instead of wire gauze, and to divide it into three parts, each
adjustable in each, and to interpose wire gauze discs between the upper
part forming the cap and medial part h", and between this latter and
the lower part, so as to keep up the draught necessary for the com-
bustion and allow the produce of the combustion to escape through the
apertures p. An iron rod q runs through the two wire gauze discs or
diaphragms, and carries at its upper part a sheet-iron disc, the diameter
of which is about equal to that inside the cylinder or the chimney;
consequently this disc is held as in the preceding improvement by the
fusible pin l, which on melting lets the sheet-iron disc fall upon the
upper wire gauze; the sheet iron disc by being carried away owing to
the weight of the rod and by intercepting the draught of air extinguishes
the lamp.
The third part of these improvements, as regards the extinguishing of
the lamp when the miner attempts to open it, consists, as illustrated in
Figs. 1 and 2, in fixing with screws or otherwise a metallic blader upon
the box a constituting the oil reservoir, the upper raised extremity of
which blade abuts, when the two upper and lower parts of the lamp
are to be unscrewed, against a gudgeon 8 fixed below a metal plate t, to
which is imparted a rotation movement on its pivot a carrying its free
extremity over and above the wick which it extinguishes. A spring v
retains by pressure this plate t over and upon the wick.
Having thus described the nature of the said improvements, and the
manner of carrying the same into effect, I would have it to be clearly
understood that I do not intend to restrict myself to the exact details
above enumerated, as these may obviously be modified without departing
from the principle of the improvements; but what I claim as novel and
original and wish to secure by Letters Patent is,-
1°. A cap or calotte, or metal plate, or any other such like analogous
contrivance answering the purpose of an extinguisher, and held sus-
pended inside the chimney of miners' safety lamps by a pin of metal

page_text: fusible at a given degree, which on melting would fall and intercept the
draught of air so as to extinguish the lamp, as herein-before fully set
forth and described.
2°. The construction of the chimney in miners' safety lamps in two
parts, the lower part of crystal and the other either of wire gauze alone,
or wire gauze and sheet iron, tin plate, or any other convenient metal
employed simultaneously in combination with the extinguisher sus-
pended by means of the fusible pin, and operating substantially in the
manner herein-before fully set forth and described.
3º. The mode of extinguishing miners' safety lamps, whenever an
unseasonable attempt is made to open them, by means of a spring or
other device, against which abuts a gudgeon fixed and acting upon a
metal plate to which is imparted a rotation movement carrying it above
the wick which it extinguishes, substantially as herein-before fully set
forth and described.
In witness whereof, I, the said Henri Adrien Bonneville, have here-
unto set my hand and seal, this Seventeenth day of October,
in the year of our Lord One thousand eight hundred and sixty-
eight.