IMPROVEMENTS IN MINERS' SAFETY LAMPS
Year: 1883

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for an
Invention of "IMPROVEMENTS IN MINERS' SAFETY LAMPS" communicated to
him from abroad by Henry Pieper of Liége, Belgium, Gun Manufacturer
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office
of the Commissioners of Patents on the 22nd August 1883.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN MINERS'
SAFETY LAMPS" [communicated to him from abroad by Henry Pieper of Liége,
Belgium, Gun Manufacturer]
According to this invention a miners safety lamp is so constructed as to require.
to be lighted after it has been securely closed the lighting being effected by the
aid of electricity and also so as to be infallibly put out if opened-or put out by
the act of closing it if the lamp be lighted before closing.
For this purpose a cylindrical casing is placed over the oil reservoir of the lamp
and is secured by a screw ring screwing on to its lower end. The top of the casing
is closed over by a plate which at its centre carries a tube to fit over the exterior of
the wick tube of the lamp and serves as an extinguisher. Above the plate is also
the ordinary glass and wire gauze cap.
When the lamp is properly closed the top of the extinguisher tube comes below
the top of the wick tube and the wick of the lamp when lighted burns without
impediment. If the lamp is opened the plate which carries the extinguisher tube
rises slowly as the screw locking ring is turned-as it rises the extinguisher tube
comes above the wick tube and extinguishes the flame.
In the same way if the lamp were lighted before closing it would be put out by
the extinguisher tube as the lamp was being closed.
When the lamp has been properly closed it is lighted by means of a small spiral
of platinum wire then brought over the wick and rendered incandescent by passing
an electric current through it.
For this purpose the wire spiral is carried by two prongs or arms standing out
from a spindle which passes up through the plate above mentioned. One arm is

page_text: insulated from the spindle the other formed with it-the spindle is acted on by a
spring to turn the spiral away from over the top of the wick. The spindle can be
turned in the opposite direction to bring the spiral above the top of the wick by
inoving sidewise a peg which passes out through a slot in the outer cylindrical
casing this slot is always covered over by a plate fixed to the peg.
When the spindle is turned so as to bring the spiral over the wick the insulated
prong is brought against an insulated arm in connection with one pole of a battery
whilst the other prong is in connection with the other pole of the battery. A
current therefore then passes through the spiral and rendering it incandescent
ignites the wick.
The battery may be an accumulator or secondary battery of a cylindrical form
fixed below the oil vessel. The case of the battery in this case made with a
central stem passing up through it. A screw is passed through this stem to screw
it to a metallic block on the bottom of the oil vessel-one pole of the battery may
be coupled to this screw. The spindle which carries the spiral will then be in
connection with this pole of the battery. The other pole of the battery may be
coupled to a metallic ring carried around the edge of the top cover of the battery.
A stem carrying the insulated arm above mentioned is carried down through the
oil vessel of the lamp and its lower end which is telescopic is pressed downwards
by a spring and made to bear upon this ring-the arm is therefore put into
communication with the second pole of the battery.
This pole of the battery may also be connected to a metallic ring around the
bottom of the battery case so that the battery may if desired be charged without
removing it from the lamp.
The battery need not form part of the lamp the lamp might be lighted from a
separate battery.
In this case the lighting may be effected by a tubular key of non-conducting
material to which two insulated wires from a battery are connected-one wire may
be connected to a metallic tube by which the exterior of the key is surrounded the
other to a metallic tongue or core in the interior of the key.
When the lamp is to be lighted the key is placed on to the end of the metal
stein by which the insulated arm is carried the exterior of the key then fits within
the lower part of the tubular passage through which this stem passes down
through the oil vessel.
The insulated arm will in this way be connected to one pole of the battery and
the body of the lamp with the other so that when the spiral is brought into
position above the top of the wick the circuit will be completed and the spiral
rendered incandescent as above explained.
Or in place of the above arrangement the stem of the fork by which the spiral
is carried may be insulated and made to pass down through the oil vessel so that
one pole of the battery may be connected to its lower end by a tubular key fitting
over it in a similar way to that above described: The other stem carrying the
single arm would then not be insulated.
When the key has been placed on to the lower end of the stem the stem may be
turned by turning the key and the spiral so brought over the wick and the circuit
completed.
The extinguisher tube of lamps constructed as above described may if desired
be provided with a lid or lids to close it over at the top whenever it is raised above
the top of the wick tube. In all the arrangements above described the completion
or breaking of the electric circuit is effected inside the lamp so that no sparks can
be produced on the outside,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sydney Pitt in the Patent Office on the 22nd February 1884.
SYDNEY PITT of Sutton in the County of Surrey. IMPROVEMENTS. IN MINERS'
SAFETY LAMPS A Communication to me from abroad by Henry Pieper of Liége,
Belgium, Gun Manufacturer
According to this Invention a miners safety lamp is so constructed as to require
to be lighted after it has been securely closed the lighting being effected by the
aid of electricity and also so as to be infallibly put out if opened-or put out by
the act of closing it if the lamp be lighted before closing.
For this purpose a cylindrical casing is placed over the oil reservoir of the lamp
and is secured by a screw ring screwing on to its lower end-The top of the casing
is closed over by a plate which at its centre carries a tube to fit over the exterior
of the wick tube of the lamp and serve as an extinguisher. Above the plate is
also the ordinary glass and wire gauze cap.
When the lamp is properly closed the top of the extinguisher tube comes below
the top of the wick tube and the wick of the lamp when lighted burns without
impediment. If the lamp is opened, the plate which carries the extinguisher tube
rises slowly as the screw locking ring is turned-As it rises the extinguisher tube
comes above the wick tube and extinguishes the flame.
In the same way if the lamp were lighted before closing, it would be put out by
the extinguisher tube as the lamp was being closed.
When the lamp has been properly closed it is lighted by means of a small spiral
of platinum wire then brought over the wick and rendered incandescent by passing
an electric current through it.
For this purpose the wire spiral is carried by two prongs or arms standing out
from a spindle which passes up through the plate above mentioned. One arm is
insulated from the spindle the other formed with it-the spindle is acted on by a
spring to turn the spiral away from over the top of the wick. The spindle can
be turned in the opposite direction to bring the spiral above the top of the wick,
by moving sidewise a peg which passes out through a slot in the outer cylindrical'
casing this slot is always covered over by a plate fixed to the peg.
When the spindle is turned so as to bring the spiral over the wick the insulated.
prong is brought against an insulated arm in connection with one pole of a battery.
whilst the other prong is in connection with the other pole of the battery.--A
current therefore then passes through the spiral and rendering it incandescent
ignites the wick.
The battery may be an accumulator or secondary battery of a cylindrical form'
fixed below the oil vessel. The case of the battery is in this case made with a
central stem passing up through it-a screw is passed through this stem to screw
it to a metallic block on the bottom of the oil vessel-one pole of the battery may
be coupled to this-screw. The spindle which carries the spiral will then be in
connection with this pole of the battery.-The other pole of the battery may
be coupled to a metallic ring carried around the edge of the top cover of the
battery.
A stem carrying the-insulated arm above mentioned is carried down through the
oil vessel of the lamp and its lower end which is telescopic is pressed downwards
by a spring and made to bear upon this ring-the arm is therefore put into
communication with the second pole of the battery.
This pole of the battery may also be connected to a metallic ring around the
bottom of the battery case so that the battery may if desired be charged without
removing it from the lamp.

page_text: Figure 1, is a side elevation of a lamp constructed as above described. Figure 2
is a vertical section through the line A. B. (Figure 5)-Figure 3 is a vertical section
through the line C D-Figure 4 is a side elevation of the oil reservoir with the
outer casing I in section and unscrewed so that it may be drawn upwards and
separated from the oil reservoir-Figure 5 is a horizontal section through the
line E F (figure 1) to show the upper side of the plate H-Figure 6 is an
underside view of this plate.
In these figures O is the oil reservoir of the lamp its sides are continued down-
wards to form a casing within which the accumulator G is carried-I is the
cylindrical casing by which the oil reservoir is surrounded P is a screw ring held
in a groove formed around the downward prolongation of the oil resorvoir and
capable of being freely turned around it.
The ring P screws on to the lower end of the casing I and secures the casing to
the oil reservoir.-A vertical slot is also formed in the casing I as shewn in
Figures 2 and 4.
The spindle of the pinion by which the wick is raised and lowered passes
through this slot.
His the plate by which the top of the casing I is closed-it comes below a
flange which passes around the interior of the casing I and is held up to this flango
by two lugs L which project inwards from two opposite sides of the casing I.
The plate H has two notches M formed in it at two opposite sides of its circum-
ference as shewn at Figure 5.-The lugs L project into these notches when the
plate H is being inserted into its place. When the plate is held up to the flange
which is around the interior of the casing I a partial turn can be given to the
plate to move the notches M from above the lugs L so that the lugs then come
below the edge of the plate and hold the plate up.
The plate H carries at its centre the tube N which fits over the exterior of the
wick tube and acts as an extinguisher as herein before explained.
The upper part of the lamp may be constructed in the manner shown in the
drawings or it may be of other suitable construction.
.The accumulator G is secured to the underside of the oil vessel O by means of
a screw at the centre of its upper side screwing into a tube at the centre of the
underside of the oil vessel as shewn at Figure 2.
One of the poles of the accumulator is as is also shewn in this figure in direct
communication with the central scrow rod a of the accumulator and so is in
communication through the body of the lamp with a small upright axis f which
carries a fork b b¹‚—The arms b. b, of the fork carry between them a spiral 8 of
platinum wire, one of the arins b is in electrical contact with the axis f whilst the
other arm b' is insulated from this axis as shewn at Figure 5.
The other pole of the accumulator is as is also shewn in Figure 2 in communication
with a metallic cap or ring which is around the upper part of the accumulator―
dd is a telescopic rod carried through and insulated from a tube which passes
vertically through the oil vessel. The two parts of the rod are respectively pressed
upwards and downwards by means of a spiral spring as shewn. The lower end d'
of the rod is in this way made to rest upon the surface of the ring d whilst the
upper end of the rod d is made to rest against the lower end of a short insulated
rod which is carried by the plate H. The rod has an arm projecting
siddewise from it against which the insulated arm b' can be made to press whenever
the platinum wire coil is brought over the wick of the lamp. his a lever arm on
the axis of the fork which carries the platinum wire coil. A spring m fixed to
the underside of the plate H bears against the arm hand keeps it pressing against
a pin r carried by a slide R. The pin is a prolongation of the stom of a knob or
button by which the slide R can be pushed to one side. Normally the spring, m
keeps the platinum coil turned aside into the position shewn by the full lines in
figure 5 but if the slide R be pressed to the right the coil will be brought above the
wick as shown by the dotted linos.

page_text: When the coil is brought into this position the insulated arm b₁ of the fork is
brought against the arm which projects from the rod d¹¹ in this way the battery
circuit is completed and the platinum wire is heated by the passage of the current
and ignites the wick.
The slide R is of such a length that it always covers the slot in the casing I through
which the stem of the slides knob or handle passes. The fork 6 b' can also be made
to serve as a cleaner for the wick.
V is a metallic ring around the lower part of the accumulator it is in metallic
connection with the ring d-and permits of the accumulator being charged without
removing it from the lamp..
The battery need not form part of the lamp-the lamp might be lighted from a.
separate battery.
In this case the lighting may be effected by a tubular key of non conducting
material to which two insulated wires from a battery are connected. One wire
may be connected to a metallic tube by which the exterior of the key is surrounded⚫
the other to a metallic tongue or core in the exterior of the key.
When the lamp is to be lighted the key is placed on to the end of the metal-
stem by which the insulated arm is carried the exterior of the key then fits within
the lower part of the tubular passage through which this stem passes down through.
the oil vessel.
:
The insulated arm will in this way be connected to one pole of the battery and
the body of the lamp with the other so that when the spiral is brought into position
above the top of the wick the circuit will be completed and the spiral rendered'
incandescent as above explained.
Figure 7 shows a vertical section of the lower part of a safety lamp constructed
in the above manner and Figure 8 a longitudinal section of the key employed when
lighting it in this latter figure the metallic core in the interior of the handle is
marked and the metal tube by which the exterior of the end of the key is
surrounded is marked g. The lamp differs only from the lamp previously described
and shewn in Figures 1 to 6 in that it does not carry a lighting battery and in that
the stem of the insulated arm d is prolonged so that the key may be applied
directly to its lower end as above described.
The lighting of the lamp is effected by the movement of the slide R as in the
previous case.
Or in place of the above arrangement the stem of the fork by which the spiral is
carried may be insulated and made to pass down through the oil vessel so that one
pole of the battery may be connected to its lower end by a tubular key fitting over
it in a similar way to that above described. The other stem carrying the single
arm would then not be insulated.
When the key has been placed on to the lower end of the stem the stem may be
turned by turning the key and the spiral so brought over the wick and the circuit
completed.
Figure 9 shews a vertical section and Figure 10 a horizontal section of the lower
part of a safety lamp constructed in this manner. Figure 11 shews a longitudinal
section of the key. As will be seen in Figure 9 the stem of the fork bb' is
insulated from the body of the lamp-its lower end is flattened and the hole in
the key is of an oblong form to fit over it so that it may be turned by the key to
bring the platinum wire coil over the wick at the time when the lamp is to be
lighted.
In other respects the lamp is constructed in a similar manner to those previously
described except that the slide R is not required.
The extinguisher tube of lamps constructed as above described may if desired be
provided with a lid or lids to close it over at the top whenever it is raised above
the top of the wick tube. In all the arrangements above described the completion or
breaking of the electric circuit is effected inside the lamp so that no sparks can be
produced on the outside.
I

page_text: Having thus described the nature of the Invention and the manner of performing
the same I would have it understood that I claim:-
First The employment in safety lamps of a tube N surrounding the wick tube
to extinguish the lamp whenever it is opened or closed substantially as described.
Second The combination of the plate H carrying the extinguisher tube N the
outer casing I surrounding the oil vessel and the screw ring P for securing it to tho
oil vessel or lower part of the lamp substantially as described.
Third. The construction of safety lamps in such manner that when securely
closed they can be. lighted by a wire heated by an electric current passed
through it.
Fourth. The combination of an accumulator carried at the bottom of a safety
lamp a wire which can be turned into position to come above or in proximity to
the wick and means for causing an electric current to pass from the accumulator
through the wire when so brought in proximity to the wick so as to heat the wire
and ignite the lamp
Fifth. The means substantially as herein before described with reference to
Figures 7 and 8 for passing an electric current through the wire employed for
lighting the lamp at the time when the lamp is to be lighted.
Sixth. The means substantially as herein before described with reference to
Figures 9, 10 and 11 for passing an electric current through the wire employed
for lighting the lamp at the time when the lamp is to be lighted.
Seventh. The construction of safety lamps to be lighted by means of an
electric current substantially as herein before described and illustrated in the
drawings annexed.
In witness whereof I the said Sydney Pitt have hereunto set my hand and seal
this Twenty first day of February in the year of our Lord One thousand eight
hundred and eighty four.