IMPROVEMENTS IN SAFETY LAMPS
Year: 1865

page_text: Sealed the 3rd November 1865, and dated the 8th May 1865.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
8th May 1865.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SAFETY LAMPS," a communication to me from abroad by
Ferdinand Sack, of Sprockhovel, near Elberfeld, in the Kingdom of Prussia,
Director of Coal Mines, to be as follows:
This Invention relates to miners' safety lamps, and consists in so con-
structing such: lamps that all danger of explosion is obviated by their employ-
ment. The upper portion of the lamp may be of the usual construction, and
composed reither wholly of wire gauze, or partly of wire gauze and partly of
glass, and may be provided or not with a metal or other chimney as has here-
tofore been adopted. The bottom rim of the upper part of the lamp where it
[Price Sd.]

page_text: is screwed on to the base containing the oil vessel consists of a metal ring, the
upper part of which is screwed externally and the lower part internally. The
external screwed portion screws into a fixed rim on the bottom of the upper
or removeable portion of the lamp and serves to keep the glass, wire gauze
cylinder, and chimney in their places, and when unscrewed admits of their
ready removal for the purpose of cleaning or otherwise; when screwed in its
place on the rim this ring is prevented from being unscrewed again till the
lamp has been opened by a pin passing from below through the moveable ring
and into the fixed rim, which pin cannot be withdrawn so long as the lamp
is closed. The internal screwed portion of the moveable ring screws into a
corresponding collar on the base or oil vessel, and thus serves to connect the
upper and lower parts of the lamp together. On one side of the wick there
is provided a hinged cap or cover, which, when allowed to close down upon
the wick, acts as an extinguisher, but when kept in a vertical position serves
as a reflector, it being made concave and polished for that purpose. The
hinge of the cap is acted on by a spring, which tends always to close the cap
and extinguish the light; the cap is kept open or in its vertical position by
any convenient arrangement of self-acting catch, which shall so operate as to
keep the cap open so long as the lamp is closed, or by the act of closing the
lamp, but shall be released and allow the cap to fall by the act of opening the
lamp, or by any accidental blow given to the lamp through falling or other-
wise, or by the heat of any inflamed gases inside the body of the lamp.
According to one arrangement of catch, which may be described as an
example, a tail piece or projection is formed on the hinged portion of the cap,
which when opened is held in that position by the inner end of a pin or
spindle inserted through an opening in the ring, and through a corresponding
notch in the screwed collar of the oil vessel; so long as this pin is in its place
it acts also as a bolt to prevent the unscrewing of the ring and upper part of
the lamp from the base. The cap is held open during the lighting of the
lamp by a moveable stop or detent inside the lamp, which bears against the
tail piece on the cap, and thereby keeps it open till the lamp is lighted and
closed. The pin or spindle is then inserted, so as to cause its inner end
to bear against the tail piece, and when inserted it is turned partly round on
its axis, so as to cause a cam projection on one side to press against the detent
and release it from the tail piece. The cap is then held open solely by the
presence of the pin; and the pin is kept in its place by the fact of the cam
projection not being able to pass through the slot in the collar of the oil
vessel when turned in the horizontal position it now occupies.
On turning
the pin or spindle, however, a quarter of a revolution, so as to bring the cam

page_text: projection into a vertical position, the pin is free to be withdrawn, and con-
sequently there being no longer any resistance to the closing spring of the cap,
the latter becomes instantly released and falls upon and extinguishes the
light; this turning of the pin may be effected either by the hand of the miner,
or by the accidental falling or striking of the lamp against any object. In
this latter case a forked lever is fitted to the outer end of the pin, which lever,
when the pin is set in its proper position, is vertical, and projects below the
bottom of the oil vessel. On the tail of this lever coming in contact with any
object it will turn the pin and so release the cap and extinguish the lamp.
It is also proposed to make the inner end of the pin of some highly brittle
material which shall fit into a square recess in the tail piece of the cap and be
broken or twisted off by the act of turning the pin to extinguish the light, and
the miner not being enabled to re-light his lamp until supplied with another
pin will be compelled to deliver up his lamp for a fresh one. By using any
highly fusible metal for the end of the pin, any excess of heat inside. the
lamp will cause the said metal to melt, and will release the cap and extinguish
the light.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 8th November 1865.,
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN HENRY
JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of May, in the year of our Lord
One thousand eight hundred and sixty-five, in the 28th year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson, my executors, administrators, or
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
"IMPROVEMENTS IN SAFETY LAMPS," a communication to me from abroad by
Ferdinand Sack, of Sprockhovel, near Elberfeld, in the Kingdom of Prussia,

page_text: Director of Coal Mines, upon the condition (amongst others) that I, the said
John Henry Johnson, my executors or administrators, by an instrument in
writing under my hand and seal, 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 John Henry Johnson, 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, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:
The said Invention relates to miners' safety lamps, and consists in so con-
structing such lamps that all danger of explosion is obviated by their employ-
ment. And in order that the said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that purpose I
shall refer to the several Figures on the Sheet of Drawings hereunto an-
nexed, the same letters of reference indicating corresponding parts in all the
Figures.
Figure 1 of the Drawings represents a partial elevation and vertical
section of the improved safety lamp; Figure 2 is a plan, with the upper part
of the lamp removed; Figure 3 is an elevation of the back of the cap hercin-
after referred to, and parts connected therewith, and the rest of the Figures
are details which I shall herein-after more particularly describe. The upper
portion of the lamp, as far as the line 1-2 (Figure 1) forms no part of this
Invention, and may be of the usual or other construction, being composed either
wholly of wire gauze or parily of wire gauze and partly of glass, as shewn in the
Drawing, and may be provided or not with a metal or other chimney, as has here-
tofore been adopted. The bottom rim of the upper part of the lamp, where it is
screwed on to the base A, containing the oil vessel, consists of a metal ring B, the
upper part of which at a is screwed externally, whilst the lower part at bis
screwed internally. The external screwed portion a screws into a rim C, fixed
permanently on the bottom of the upper or removeable portion of the lamp,
and serves to keep the glass cylinder D, wire gauze E, and chimney F in their
places, and when unscrewed admits of their ready removal for the purpose of
cleaning or otherwise. When screwed in its place on the rim this ring B is
prevented from being unscrewed again till the lamp has been opened by a
pin c, passing from below through the moveable ring B, and into the fixed
rim C, which pin cannot be withdrawn so long as the lamp is closed, a head

page_text: being formed on the lower end of the pin which enters a countersunk hole in
the ring B, and thus prevents the withdrawal of the pin from above. The
internal screwed portion b of the moveable ring B screws on to a corresponding
collar d, on the base of the lamp or oil vessel A, and thus serves to connect
the upper and lower parts of the lamp together. On one side of the wick H
there is provided a hinged cap or cover I, which, when allowed to close down
upon the wick, as shown by dotted lines in Figure 1, acts as an extinguisher,
but when kept in a vertical position serves as a reflector, it being made con-
cave and polished for that purpose. The hinge e of the cap is acted on by a
spring, which tends always to close the cap and extinguish the light. The
cap is kept open or in its vertical position by any convenient arrangement of
self-acting catch, which shall so operate as to keep the cap open so long as
the lamp is closed, or by the act of closing the lamp, but shall be released and
allow the cap to fall by the act of opening the lamp, or by any accidental blow
given to the lamp through falling or otherwise, or by the heat of any inflamed
gases inside the body of the lamp. According to one arrangement of catch,
illustrated in the Drawing, and which may be described as an example, a tail
piece or projection is formed on the hinged portion of the cap, which, when
opened, is held in that position by the inner end h of a pin or spindle K, shown
detached at Figures 4 and 5, inserted through an opening in the ring B. and
through a corresponding notch in the screwed collar d of the oil vessel. So
long as this pin is in its place it acts also as a bolt to prevent the unscrewing
of the ring B and upper part of the lamp from the base. The cap I is held
open during the lighting of the lamp by a moveable stop or detent i (Figures
2 and 3) inside the lamp which bears against the tail piece g on the cap when
the latter is in a vertical position, and thereby keeps it open till the lamp is
lighted and closed, or put together. The pin or spindle K is then inserted
so as to cause its inner end to bear against the tail piece g, and when inserted
it is turned partly round on its axis so as to cause a cam projection k (Figures
4 and 5) formed on one side of the piece, to press against the part 1 of the detent i,
and by pushing it back to release the end of the detent from contact with the tail
piece. The cap is then held open solely by the presence of the pin K, the
inner end of which bears against the tail piece g, and the pin is retained in its
place by the fact of the cam projection k not being able to pass out through
the slot in the collar d of the oil vessel when turned in the horizontal position
it occupies in Figures 1 and 2 of the Drawings; on turning the pin or
spindle K, however, a quarter of a revolution, so as to bring the cam pro-
jection k into a vertical position above the pin K, the latter is free to be with-
drawn, and consequently there being no longer any resistance to the closing

page_text: spring or the cap, the latter becomes instantly released and falls upon and
extinguishes the light. This turning of the pin K may be effected either by
the hand of the miner or by the accidental falling or striking of the lamp
against any object. In this latter case a forked lever or crutch L (Figure 6)
is fitted to the outer end of the pin K, which lever when the pin is set in its
proper position remains vertical and projects below the bottom of the oil
vessel, as shown in Figure 1. On the tail of this lever coming in contact
with any object, and thereby turning the pin K a quarter of a revolution, so as
to bring the cam into a vertical position above the pin, the pin will fly out
and the cap will be released, and falling down upon the flame will extinguish
the lamp. It is also proposed to make the inner end h of the pin K of some
highly brittle material, such as glass, slate, or plumbago, which shall be fitted
into a socket m, made to receive it in the end of the pin (see Figure 7) whilst
its squared end fits into a square recess (shown in Figures 1 and 3) in the tail
piece of the cap, so that it shall be broken or twisted off by the act of
turning the pin to extinguish the light. As the miner will not be enabled to
re-light his lamp until supplied with another pin, he will be compelled to
deliver up his lamp for a fresh one. By using any highly fusible metal for
the end (Figure 7) of the pin K, any excess of heat inside the lamp
will cause the said metal to melt, and will release the cap and extinguish the
light.
Having now described and particularly ascertained the nature of the said
Invention, and in what manner 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 herein-
before in part recited Letters Patent is,-
First, the so constructing miners' safety lamps that the opening of the
same will effect the extinguishing of the light, substantially in the manner
herein-before described.
Second, the application and use to and in miners' safety lamps of a self-
acting extinguisher for putting out the light so soon as the lamp is attempted
to be opened; substantially as herein-before described.
Third, the combination of the pin K, cam k, and detent or bolt i, with the
tail g of the extinguisher, all operating substantially in the manner and for
the purpose herein-before described.
Fourth, the application and use of the forked lever or crutch L, substantially
as and for the purpose herein-before described.
Fifth, the application and use to and in miners' safety lamps of the loose
ring B and pin c, substantially as and for the purpose herein-before described.

page_text: Sixth, the making the inner portion or end of the pin K of any suitable
brittle material, or of a readily fusible metal, as and for the purpose herein-
before specified.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Eighth day of November, in
the year of our Lord One thousand eight hundred and sixty-five.
J. HENRY JOHNSON. (L.S.)