Improvements in Safety Lamps.
Year: 1891

page_text: Date of Application, 27th June, 1891
Complete Specification Left, 27th Apr., 1892-Accepted, 28th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Safety Lamps.
We JOSEPH PRESTWICH of 8 Irwell Park Eccles in the County of Lancaster
Agent, and THE PROTECTOR LAMP AND LIGHTING COMPANY LIMITED also of
Eccles in the said County, Lamp Manufacturers do hereby declare the nature of
this invention to be as follows:-
This invention relates principally to the class of safety lamps for which I applied
for Letters Patent No. 18226 dated 12th day of November 1890, but parts of my
invention are also applicable to other forms of safety lamps. The objects of the
invention are to improve and economize the construction of the lamps.
In the first place cast the body of the oil reservoir of the lamp and the top in
one piece of a cylindrical form with the outer rin projecting (say) about half an
inch above the top, and the inner side of the top, and the inner side of the top rim
I chase with an internal screw thread.
At or near the centre of the top is an opening for the wick holder and outside
this is a raised rim, also chased on the inside to receive a screwed ring for keeping
the wick holder in place.
The bottom part of the outer rim of the oil receiver is made with a shoulder or
rebate onto which is soldered the bottom which is in the form of a plain disc.
The lamp may be fitted with a hollow cone surrounding the wick tube and
And the wick
provided with holes round its base for the supply of air to the wick.
tube may be provided with an extinguishing shell as described in the Specification
No. 18226 above referred to.
I also provide a ring of about the same diameter as the top of the reservoir and
on the circumference thereof I chase a screw thread of the same pitch as that on
the inside of the top rim of the oil reservoir so that this ring can be screwed into the
same.
The top rim however is deeper than the ring so that when the latter is screwed
in it leaves a space of about one quarter of an inch (more or less) below it, for a
purpose hereinafter mentioned.
This bottom ring is permanently attached by three four or more pillars to an
upper ring to which is fixed the metal cover.
The bottom ring is also chased with a screw thread on the insile into which
screws the "following-plate" which supports the glass cylinder or cylinders, and
where two glass cylinders are used the ring is slotted and covered with a ring of
wire gauze at the part between the two cylinders.
The wick tube is provided with a star-wheel for raising and lowering the wick
(or a tube outside the same) and this wheel is mounted on one end of a small tube
which passes through the space between the bottom ring and the top of the oil
reservoir (above mentioned) and through a slot or hole in the outer rim to the
outside of the lamp, where it is provided with a milled button for turning the same.
Inside this tube passes a thin wire provided with a button at the outside and at
its inner end with a pricker wire" which can be moved to and fro and also pushed
backwards and forwards by means of the exterior button so as to cause the
"pricker wire to break off the crust and open up the wick if it should become
corroded the wick raiser and "pricker wire may also be arranged to work
::
•
through the bottom instead of the side if preferred.
The locking device is constructed as follows. I provide a shield of brass or other
inetal capable of sliding up and down on two of the pillars. This shield is in the
form of a quadrant lying on the bottom ring and has a square hole about the centre

page_text: through which projects a square block firmly fixed to or cast on the upper surface
of the ring.
The shield is also made with a lip in which is made a notch which embraces the
tube of the wick raiser so as to prevent the lamp from being unscrewed until the
shield has been raised up, or instead of this where the wick raiser. and "pricker
wire "
are not employed I sometimes use a pin or plug.
A horizontal hole is made through the block above the top of the shield and a
lead rivet or screw being passed through and secured in the usual manner will
prevent the shield from being raised and the lamp unscrewed without destroying
the rivet.
This lamp is applicable for burning any kind of oil or spirit usually employed in
mines.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Safety Lamps.
We JOSEPH PRESTWICH of 8 Irwell Park Eccles in the County of Lancaster
Agent, and THE PROTECTOR LAMP AND LIGHTING COMPANY LIMITED also of
Eccles in the said County, Lamp Manufacturers, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates principally to the class of safety lamps for which Joseph
Prestwich applied for and obtained Letters Patent No. 18226 dated 12th day of
November 1890 but parts of this invention are also applicable to other forms of
safety lamps. The objects of the invention are to improve and economize the
construction of the lamps.
And the same will be readily understood on reference to the accompanying sheet
of drawings and the following explanation thereof.
Fig. 1 is an elevation partly in section of a safety lamp constructed according to
our invention.
Fig. 2 is a detached view of the wick adjusting device and the pricker for opening
up the wick as hereinafter more particularly described.
Fig. 3 is a horizontal section of the same (through about the line A-B on Fig. 1)
the glass cylinders being removed.
Fig. 4 is an elevation of the lower part thereof, the wick adjusting tube and
pricker wire being in section.
In the first place we cast the body of the oil reservoir a of the lamp and the
top a' in one piece of a cylindrical form with the outer rim a² projecting (say)
about half an inch above the top, and the inner side of this top rim a² we chase
with an internal screw thread.
At or near the centre of the top a¹ is an opening for the wick holder and
outside this is a raised rim a³ also chased on the inside to receive a screwed ring c
for keeping the wick holder b in place.
The bottom part of the outer rim of the oil receiver a is made with a shoulder
or rebate onto which is soldered the bottom a', which is in the form of a plain disc.
The lamp may be fitted with a hollow cone d surrounding the wick tube and
provided with holes round its base for the supply of air to the wick. And the wick
tube may be provided with an extinguishing shell (not shewn), as described in the
Specification No. 18226 above referred to.
We also provide a ring of about the same diameter as the top of the reservoir,
and on the circumference thereof we chase a screw thread of the same pitch as
that on the inside of the top rim a² of the oil reservoir, so that this ring can be
screwed into the same.

page_text: The top rim a however is deeper than the ring so that when the latter is
screwed in, it leaves a space of about one quarter of an inch (more or less) below it
(as shewn), for a purpose hereinafter mentioned.
This bottom ring is permanently attached by three, four or more pillars f¹ to
an upper ring, to which is fixed the metal cover g.
The bottom ring is also chased with a screw thread on the inside into which
screws the "following-plate" which supports the glass cylinder or cylinders, and
where two glass cylinders are used, as shewn, the ring c is slotted see Fig. 3
and covered with a ring of wire gauze see Fig. 1 at the part between the two
cylinders and h'.
The wick tube bis provided with a star or toothed wheel see Fig. 2 for
raising and lowering the wick (or a tube outside the same) and this wheel is
mounted on one end of a small tube 1, which passes through the space between the
bottom ring and the top a' of the oil reservoir (above mentioned) and, through a
slot or hole in the outer rim a², to the outside of the lamp, where it is provided
with a milled button * for turning the same.
Inside this tube I passes a thin wire m provided with a button m* at the outside,
and at its inner end with a "pricker wire" or plate n which can be moved to and
fro and also pushed backwards and forwards by means of the exterior button m*,
so as to cause the "pricker wire or plate i to break off the crust and open up the
wick if it should become burnt "bard."
"
In some cases the wick tube may be so arranged that the tube and wheel k and
the wire m may pass into the lamp below the top a¹ of the reservoir..
The wick raiser and pricker wire may also be arranged to work through the
bottom instead of the side if preferred.
The locking device is constructed as follows:-We provide a shield of brass or
other metal capable of sliding up and down on two of the pillars. This shield o
is in the form of a quadrant (see Fig. 3) lying on the bottom ring, and has a square
hole about the centre, through which projects a square block p, firmly fixed to or
cast on the upper surface of the ring f
The shield is also made with a lip o¹ in which is made a notch which embraces
the tube of the wick raiser k so as to prevent the lamp from being unscrewed
until the shield o lias been raised up, or instead of this, where the wick raiser and
pricker wire are not employed, we sometimes use a pin or plug.
A horizontal hole is made through the block p above the top of the shield and a
lead rivet or screw being passed through and secured in the usual manner will
prevent the shield o from being raised and the lamp unscrewed without destroying
the rivet.
This lamp is applicable for burning any kind of oil or spirit usually employed in
mines.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
1. The improved construction and arrangement of our safety lamp substantially
as hereinbefore described and illustrated by the annexed drawings.
2. The combination with the wick tube of a safety lamp of a wick raiser
actuated by a tube passing to the outside of the lamp and a pricker-wire or plate,
actuated by a wire passing through the tube last mentioned substantially as herein-
before described and illustrated by the annexed drawings.
Dated this 26th day of April 1892.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.