IMPROVEMENTS IN SAFETY LAMPS FOR MINING AND OTHER PURPOSES.
Year: 1869

page_text: LETTERS PATENT to Arthur Hamilton Gilmore, of Edinburgh, in the
County of Mid Lothian, Commander, R.N., for the Invention of
"IMPROVEMENTS IN SAFETY LAMPS FOR MINING AND OTHER PURPOSES.'
Sealed the 8th March 1870, and dated the 14th September 1869.
PROVISIONAL SPECIFICATION left by the said Arthur Hamilton
Gilmore at the Office of the Commissioners of Patents, with his
Petition, on the 14th September 1869.
I, ARTHUR HAMILTON GILMORE, of Edinburgh, in the County of Mid
Lothian, Commander, R.N., do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SAFETY LAMPS FOR MINING AND OTHER
PURPOSES," to be as follows:-
According to my improvements in safely lamps the immediate and
certain extinction of the flame is ensured upon any attempt being made
to open the lamp, so that all possibility of explosion by the exposure of

page_text: the flame is avoided, thereby affording absolute security when used in
mines, magazines, spirit rooms, holds of ships, and other places con-
taining inflammable gases, vapors, or materials.
According to one arrangement I fit a central cap or extinguisher to
slide up and down in vertical guide rods extending downwards from the
upper part of the lamp to within a short distance of the flame. The
extinguisher is provided with a cross head, and above it is placed a spiral
spring, which pressing on the top of the extinguisher operates its descent
in the guides before mentioned. When the lamp is to be ignited for use
the extinguisher and spring is compressed at the upper part of the lamp
by means of two rods connected by a ring at their upper ends. Each of
these rods is further provided with a small horizontal quadrant-shaped
piece serving as a support for the ends of the cross head above mentioned
as fixed on the extinguisher, and serving to maintain the latter in its
raised position. The lower end of one (or both) of these sustaining rods
is furnished with a projecting catch, which when the extinguisher is raised
is caused to rest upon an inner projecting ledge fixed at the lower part
of the wire gauze or other cage. This wire cage is screwed on to the oil
holder in the usual manner, and the latter is provided with a raised nib
or projection on its upper surface, which during the last half turn (in
screwing the wire cage to the oil holder) comes in contact with the lower
end of the sustaining rod and removes it from its position on the ledge,
so allowing the ends of the sustaining rods to drop down into recesses in
the oil holder. By this means immediately any attempt is made to
uncover the flame by unscrewing the wire gauze from the oil holder or
to unlock the lamp the projecting nib again comes in contact with the
:sustaining rod, but in the reverse direction, and on turning it round
together with the ring to which it is attached at top removes the
quadrant-shaped part from under the cross piece of the extinguisher,
wwhich is then released. The extinguisher is thus free to be forced down
in its guides on to the wick by the spiral spring so as to completely
extinguish the light before the lamp is opened. The same result may
also be attained by the aid of a rod passing up through the lamp and
attached to a cross head, which takes under a stud connected with a
short length of wire passing down through the centre of the spiral spring
and attached to the extinguisher. As long as the cross head is engaged
with the stud the spiral spring will be compressed in the upper part of the
lamp, but on an attempt being made to open the lamp the rod in turning

page_text: throws back the cross head and releases the spring, which descends on to
the wick.
According to another arrangement I mount the extinguisher at one
end of a lever whose other end is hinged to one side of the lamp on a
level with the top of the wick. When the lamp is required for use the
extinguisher carrier is raised to a vertical position, where it is held by
a retaining lever mounted on a pivot at right angles to that of the
extinguisher carrier, both these parts being carried on a plate fixed at
one side of the lamp. The lower end of this vertical retaining lever is
furnished with a hinged piece, which is free to swing in ono direction
only so as to allow a projection on the oil holder to pass when screwing
the parts of the lamp together without releasing the extinguisher.
Should however an attempt be made to detach the upper part of the
lamp from the oil holder by unscrewing the parts or to unlock the same
the projection on said holder will abut against the jointed end in the
reverse direction so as to oscillate the retaining lever and disengage the
extinguisher rod, which is thus released. The extinguisher being fur-
nished with a spring is at once caused to fall on to the wick, thereby
extinguishing the flame, and being weighted it will continue to press ou
the wick until the lamp is opened.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur Hamilton Gilmore in the Great Seal Patent
Office on the 14th March 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
HAMILTON GILMORE, of Edinburgh, in the County of Mid Lothian,
Commander, R.N., send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of September, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Arthur Hamilton Gilmore, Her special
licence that I, the said Arthur Hamilton Gilmore, my executors, adminis
trators, and assigns, or such others as I, the said Arthur Hamilton
Gilmore, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter

page_text: 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 FOR MINING AND OTHER PURPOSES," upon the
condition (amongst others) that I, the said Arthur Hamilton Gilmore,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Arthur Hamilton Gilmore, do hereby
declare the nature of my 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 two Sheets of
Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say) :-
According to my improvements in safety lamps the immediate and
certain extinction of the flame is ensured upon any attempt being made
to open the lamp, so that all possibility of explosion by the exposure of
the flame is avoided, thereby affording absolute security when used in
mines, magazines, spirit rooms, holds of ships, and other places con-
taining inflammable gases, vapors, or materials.
According to one arrangement I fit a central cap or extinguisher to
slide up and down in vertical guide rods extending downwards from the
upper part of the lamp to within a short distance of the flame. The
extinguisher is provided with a cross head, and above it is placed a spiral
spring, which pressing on the top of the extinguisher operates its descent
in the guides before mentioned. When the lamp is to be ignited for
use the extinguisher and spring is compressed at the upper part of the
lamp by means of two rods connected by a ring at their upper ends.
Each of these rods is further provided with a small horizontal quadrant-
shaped piece, serving as a support for the ends of the cross head above
mentioned as fixed on the extinguisher, and serving to maintain the
latter in its raised position. The lower end of one or both of these
sustaining rods is furnished with a catch, which when the extinguisher
is raised is caused to rest upon an inner projecting ledge fixed to the
lower part of the wire gauze or other cage. This wire cage is screwed on

page_text: to the oil holder in the usual manner, and the latter is provided with a
raised nib or projection on its upper surface, which during the last half
turn (in screwing the wire cage to the oil holder) comes in contact with the
lower end of the sustaining rods, causing them to drop down into recesses
in the oil holder. By this means immediately any attempt is made to
uncover the flame by unscrewing the wire gauze from the oil holder or
to unlock the lamp the projecting nib again comes in contact with the
sustaining rod, but in the reverse direction, and on turning it round
together with the ring to which it is attached at top removes the
quadrant-shaped part from under the cross piece of the extinguisher,
which is then released. The extinguisher is thus free to be forced down
in its guides on the wick by the spiral spring so as to completely
extinguish the light before the lamp is opened. The same result may
also be attained by the aid of a rod passing up through the lamp, and
attached to a cross head which takes under a stud connected with a
short length of wire passing down through the centre of the spiral spring
and attached to the extinguisher. As long as the cross head is engaged
with the stud the spiral spring will be compressed in the upper part of
the lamp, but on an attempt being made to open the lamp the rod in
turning throws back the cross head, and releases the spring, which
descends on to the wick.
According to another arrangement I mount the extinguisher at one
end of a lever whose other end is hinged to one side of the lamp on a
level with the top of the wick. When the lamp is required for use the
extinguisher carrier is raised to a vertical position, where it is held by a
retaining lever mounted on a pivot at right angles to that of the extin-
guisher carrier, both these parts being carried on a plate fixed at one side
of the lamp. The lower end of this vertical retaining lever is furnished
with a hinged piece, which is free to swing in one direction only to
allow a projection on the oil holder to pass when screwing the parts of
the lamp together without releasing the extinguisher. Should however
any attempt be made to detach the upper part of the lamp from the oil
holder by unscrewing the parts or to unlock the same the projection on
said holder will abut against the jointed end in the reverse direction so
as to oscillate the retaining lever and disengage the extinguisher rod,
which is thus released. The extinguisher being furnished with a spring
is at once caused to fall on to the wick, thereby extinguishing the flame,
and being weighted will continue to press on the wick until the lamp
is opened.

page_text: Figures 1 to 4 illustrate one arrangement of safety lamp of my In-
vention; Figure 1 being a central vertical section showing the lamp as
set for use; Figure 2 is a similar section showing the extinguisher forced
'down by its spring on to the wick, and the light extinguished; Figure 3
is a sectional plan taken on line 1, 2, Figure 1, whilst Figure 4 is a
plan of the oil holder or base of the lamp taken on line 3, 4, Figure 1.
A is the extinguisher or cap placed centrally within the lamp to
slide on vertical guide rods B. These rods B, of which there are two or
more, are fixed at the upper part of the lamp, and extend downwards to
about the level of the wick, where they are united in a ring a, which
serves as a stop to limit the motion of extinguisher A.
C is a spiral
spring placed above extinguisher A, on which said spring bears, and
when released serves to operate the descent of the extinguisher on the
guides B before mentioned. The extinguisher A is secured to a cross
piece b whose ends b' project on either side, as shown, and take a
bearing on two flanges e formed within a ring D mounted on sustaining
rods E, E. By the aid of these sustaining rods the extinguisher is
raised by hand and the spring C compressed, as shown in Figure 1. To
maintain the parts in this position whilst the oil holder or base F is
being connected to the upper part of the lamp, the longer rod E' is
provided with a catch which takes on to a projecting ledge d formed on
the inside of the wire cage framing G of the lamp. The oil holder F is
provided with a raised nib or projection g on its upper surface (sec plan
Figure 4) for operating the extinguisher in the following manner :-The
extinguisher A being raised as before described the cage G and oil holder
are screwed together as usual, and during the last half turn and just
before the parts are quite screwed up the projection f comes in contact
with the lower end of rod E', which is thereby removed from its bearing
on ledged and is held by the pressure of the spring on the top surface of
the oil holder F. The lamp is now set and ready for use where required,
and should any attempt be made to tamper with the lamp by unscrewing
the oil holder from the cage G the light will be instantly extinguished,
as during the first revolution of the oil holder in unscrewing it (sec
Figure 2) the projection f comes in contact with and carries round the
sustaining rod E', and with it the ring D, to the position shown in red
lines Figure 3, removing the supporting ledges e from beneath the
projections of the extinguisher, which is thus free to be forced down

page_text: on its guides B on to the wick and extinguish the light, as shown
in Figure 2, which descent is immediately operated by the spiral
spring C.
Figure 5 is a part sectional elevation of another arrangement of
extinguisher for safety lamps. In this case the extinguisher consists of a
disc g carried at the extremity of an arm h pivoted at i (and on a level
with the top of the wick) to a plate; secured at one side of the lamp
within the wire cage. The oil holder F having been removed the extin-
guisher g is raised by hand to the red line position, where it is retained
by a spring catch k placed at one side of the extinguisher, as seen more
clearly in the detached view Figure 6. This catch k consists of a lever
pivoted at right angles to the extinguisher lever h and mounted on
plate j, which also carries the spring k¹ of said retaining lever or catch.
To the plate j is also attached the spring for operating the extin-
guisher lever, to the rear end of which it is connected, as shown, so that
on the catch k being released the extinguisher g will be immediately
brought down on the wick to extinguish the light, as shown in Figure 5.
The release of the catch k is effected by means of a spring projection m
carried on the top surface of the oil holder F, shown in plan Figure 7.
This spring m on the lamp being screwed up comes during the last turn
in contact with and is depressed by the lower end of lever k which it
passes, as shown in red lines in Figure 5. On turning the oil holder F
in the reverse direction for unscrewing the spring m bears forcibly
against and oscillates lever k, so releasing the extinguisher, which is
immediately brought down on the wick, as before described. Another
mode of retaining the extinguisher is shown in Figures 8 and 9. In
this case the extinguisher g is mounted as before, but is retained in the
raised position by the aid of a rod n jointed to arm h, as shown, and
working through a guide o carried on plate j. This rod n is toggle
jointed at the centre, and is provided with a step n¹ at its lower end,
which when said rod is straightened and the extinguisher raised is
caused to bear on a ledge p fixed to the platej before mentioned. The
extinguisher is thus kept raised whilst the two parts of the lamp are
being put together. The top of the oil holder F is screwed firmly up
against the lower end of rod n, so that immediately it is unscrewed the
lower part of the toggle 'n will be displaced and removed from its
position on ledge p, as shown in red line in Figure 9, so as to release the
extinguisher g, which is immediately brought down by the spring / as
before on to the wick for the purpose of extinguishing the flame.

page_text: Having described the nature of my Invention, and the manner of
performing the same, I declare that what I claim as my Invention,
to be protected by the herein-before in part recited Letters Patent
is,-
1st. The combination and arrangement of parts described and illus-
trated with reference to Figures 1, 2, 3, and 4 of the Drawings, together
with the modification of the same for causing the light in the safety
lamp to be instantaneously extinguished should an attempt be made to
open the lamp.
2ndly. The arrangements for effecting the same object described and
illustrated in Figures 5, 6, 7, 8, and 9 of the Drawings.
In witness whereof, I, the said Arthur Hamilton Gilmore, have
hereunto set my hand and seal, this Eleventh day of March, in
the year of our Lord One thousand eight hundred and seventy.
ARTHUR HAMILTON GILMORE. (L.S.)