IMPROVEMENTS IN SAFETY LAMPS
Year: 1878

page_text: LETTERS PATENT to John Williamson, of Hednesford, in the County of
Stafford, Mining Engineer, for the Invention of "IMPROVEMENTS IN SAFETY
LAMPS."
Sealed the 13th August 1878, and dated the 15th February 1878.
&
PROVISIONAL SPECIFICATION left by the said John Williamson at the Office
of the Commissioners of Patents on the 15th February 1878.
JOHN WILLIAMSON, of Hednesford, in the County of Stafford, Mining Engineer.
IMPROVEMENTS IN SAFETY LAMPS."
My Invention consists of a safety lamp with improved light and double safety
In carrying out my Invention I construct a compound or double lamp, that is,
the internal parts with the oil vessel, top, and wires form a complete safety lamp,
and the outer gauze and glass with oil vessel, top, and wires form a second, so that
if the outer gauze or glass or both are injured, the lamp will be safe; also if the
inner glass and gauze or perforated cap become defective, the lamp will still be safe
to detect an explosive gas, or to use whilst the outer parts are entire.
"
"
The lamp burns with a steady bright flame in air travelling at a high velocity.
In manufacturing this lamp I form the oil vessel much the same as a clanny"
lamp, but the body ring is formed with an air chamber similar to the "Stephenson
lamp; into this body ring the glass ring is screwed, and is turned to support both
glasses; I drill or form holes about one-eighth of an inch in diameter all round this
ring, and place a band of gauze in front thereof, so that when in position the air
passes through the air vessel into the body ring to the glass ring, it then finds its way.
through the glass ring at its periphery to the under side towards the centre,
where it takes an upward current to the flame, and improves the combustion
Price Rid

page_text: by impinging upon it, the inner glass with its cap reaches to the top of the outer
gauze, so as to prevent shake; the outer glass is an ordinary "clanny," the inner
one a "Stephenson" with perforated copper cap or gauze.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Williamson in the Great Seal Patent Office on the 14th August
1878.
JOHN WILLIAMSON, of Hednesford, in the County of Stafford, Mining Engineer.
"IMPROVEMENTS IN SAFETY LAMPS."
My Invention consists of a non-explosive safety lamp with improved light and
double safety.
In carrying out my Invention I construct a compound or double lamp, that is,
the internal parts with the oil vessel, top, and wires form a complete safety lamp,
and the outer gauze and glass with oil vessel, top, and wires form a second, so that
if the outer gauze or glass or both are injured, the lamp will be safe; also if the
inner glass and gauze or perforated cap become defective, the lamp will still be safe
to detect an explosive gas, or to use whilst the outer parts are entire.
The lamp burns with a steady bright flame in air travelling at high velocity.
In manufacturing this lamp I form the oil vessel much the same as a clanny
lamp, but the body ring is formed with an air chamber similar to the Stephenson
lamp, into this body ring the glass ring is screwed, and is turned to support
both glasses; I drill or form holes, about one-eighth of an inch in diameter, all
round this ring, and place a band of gauze in front thereof, so that when in
position, the air passes through the air vessel in the body ring to the glass ring,
it then finds its way through the glass ring at its periphery to the under side
towards the centre where it takes an upward current to the flame, and improves
the combustion; by impinging upon it the inner glass with its cap reaches to the
top of the outer gauze, so as to prevent shake; the outer glass is an ordinary clanny,
the inner one a Stephenson, with perforated copper cap or gauze.
Having thus set forth the nature of my Invention, I next proceed to describe it
with reference to the Drawings, and to the letters and figures marked thereon.
Figure 1 is an elevation of a lamp, according to my Invention.
Figure 2 is a section through the centre; Figure 3 is an elevation of the glass and
air ring; and Figure 4 is a section of the same.
The letters will refer to each Figure where the parts are visible.
In Figure 1 and 2, at a will be seen the part of the lamp where the air enters
flame proof holes; it then travels in the direction of the dotted line a¹, having to pass
standard gauze at b, is carried by the dome c to the flame d, and the gases produced
by combustion are carried away through the perforated cap at the top of the inner
glass e at f; the outer glass is shewn at g, both glasses being supported by the
ring g', see Figures 3 and 4, also shewn in Figure 2, near the letters 6 & c; this

page_text: ring is screwed to fit the body ring h in the screw part, and also at the top
where the lower part of the outer glass rests, the oil vessel i is the usual clanny
bottom.
Having now described the nature of my Invention, and the manner of carrying
it into effect, I wish it to be understood that I do not claim using two glasses, as
that has been done before, but what I claim is, the ring, Figures 3 and 4, in connection
with the glasses in the manner shewn, so as to bring or pass the air to the flame
safely, and I claim to use the said ring in this and other safety lamps.
In witness whereof, I, the said John Williamson, have hereunto set my hand
and seal, this the Twelfth day of August, One thousand eight hundred and
seventy-eight.
JOHN WILLIAMSON. (LS.)