IMPROVEMENTS IN MINERS' SAFETY LAMPS
Year: 1879

page_text: LETTERS PATENT to James Mason Douglas, of No. 6, Howard Place, Edinburgb,
for the Invention of "IMPROVEMENTS IN MINERS' SAFETY LAMPS."
Sealed the 5th December 1879 and dated the 2nd September 1879
PROVISIONAL SPECIFICATION left by the said James Mason Douglas at
the Office of the Commissioners of Patents on the 2nd September 1879.
JAMES MASON DOUGLAS, of No. 6, Howard Place, Edinburgh.
IN MINERS' SAFETY LAMPS."
"IMPROVEMENTS
This Invention has for its object improvements in the internal mechanism of
miners' safety lamps, by which the person using the lamp is prevented from opening
the same so as to expose the naked flame to the air.
For the purpose of explaining more fully the nature of my Invention I refer to
the Drawings herewith, and they may be described as follows:-
Figure 1 shows the upper portion or cover of the ordinary Davy lamp used by
niners; Figure 2 shows the body or box of such a lamp; Figure shows the
internal mechanism of my improved lamp; Figure 4 shews the portions of the said
internal arrangement drawn double the true size, and Figure 5 shews the sheath
with which I cover the internal mechanism to prevent the wick fouling the same.
In each of the Drawings the same letters represent the same parts.
I now proceed to describe the improvements which I have made upon the
lamp.
A is a section of the upper flange of the lamp box showing the screw thereon
made to receive and fix the upper portion or cover of the lamp; L is a portion of
the lower flange of the lamp cover, showing on the outside thereof the screw which
fits into and fixes it to the upper flange A of the lamp box, and on the inside
showing a toothed wheel which operates upon the toothed wheel C after
mentioned.
B is the screw on the vertical spindle E', which serves the purpose of keeping the
toothed wheel C in position.
C is a toothed wheel fixed to the hollow upright spindle D, and which D works
upon the upright spindle E'. To E¹ is attached a bevilled toothed wheel E. The
hollow spindle D is fitted with a clutch working into a corresponding clutch affixed
to the lower part of the spindle E', and the bevilled toothed wheel E.
[Drine CII

page_text: F is another bevilled toothed wheel fixed to a horizontal spindle F². The
wheel Fl works at right angles with and into the wheel E². The spindle F2 carries
upon it a section of a skeleton drum G through which the wick is passed.
H supports the spindle F2; K is the top plate of the lamp box in which is
inserted the wick holder.
When the lamp is lighted the cover is put on and screwed to the lamp box in
the ordinary way. The toothed wheel L being turned has the effect of causing the
toothed wheel C also to revolve, but when screwing on the cover the toothed
wheel C is made to revolve in such a way that the clutch upon D slides over the
corresponding clutch affixed to the spindle E¹ without causing the bevilled wheel E²
to revolve.
When however an attempt is made to unscrew the cover of the lamp from the
lamp box, the clutch on D catches the corresponding clutch affixed to the spindle E'
and causes the bevilled wheel E to revolve, which in its turn causes the bevilled
wheel F, the spindle F, and the skeleton druin G. all to revolve.
This has the effect of withdrawing the wick from the burner, and of extinguishing
it. It is thus impossible for any one using the lamp to attempt to unscrew the
cover from the lamp box, without at once extinguishing the light.
The only use of the sheath J. shown on Figure 5 is to prevent the wick from
becoming entangled in the toothed wheels or other portion of the gearing.
Although in the Drawings the Davy lamp has been shown, my improvements can
be attached to any of the ordinary lamps used by miners.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Mason Douglas in the Great Seal Patent Office on the 1st
March 1880.
JAMES MASON DOUGLAS, of No. 6, Howard Place, Edinburgh. "IMPROVEMENTS IN
MINERS' SAFETY LAMPS."
This Invention has for its object improvements in the internal mechanism of
miners' safety lamps, by which the person using the lamp is prevented from
exposing the naked flame to the air by opening the lamp.
For the purpose of explaining more fully the nature of my Invention I refer to
the Drawings herewith, and they may be described as follows:-
Figure 1 shows the upper portion or cover of the ordinary Davy lamp used by
miners Figure 2 shows the body or box of such a lamp; Figure 3 shows the
internal mechanism of-my improved lamp; Figure 4 shows the portions of the said
internal arrangement drawn double the true size, and Figure 5 shows the sheath
with which I cover the internal mechanism to prevent the wick fouling the
same.
In each of the Drawings the same letters represent the same parts.
I will now proceed to describe the improvements which I have made upon the
lamp.
A is a section of the upper flange of the lamp box showing the screw thereon
made to receive and fix the upper portion or cover of the lamp. L is a portion of
the lower flange of the lamp cover showing on the outside thereof the screw
which fits into and fixes the cover to the upper flange A of the lamp box. The
innerside of the flange L is made in the form of a toothed wheel, and operates upon
the toothed wheel C after mentioned.
B is the screw on the vertical spindle E¹, which serves the purpose of keeping
the toothed wheel C in position. C is a toothed wheel fixed to the hollow upright
spindle D, and which spindle D works upon the upright spindle E'. To E¹ is
attached a bevilled toothed wheel E. The hollow spindle I) is fitted with a clutch
working into a corresponding clutch affixed to the lower part of the spindle E' and
the bevilled toothed wheel E².
F is another bevilled toothed wheel fixed to a horizontal spindle F2. The
wheel F¹ works at right angles with and into the wheel E. The spindle F2 carries
upon it a section of a skeleton drum G through which the wick is passed.
H supports the spindle F2; K is the top plate of the lamp box in which is
inserted the burner or wick holder M.
When the lamp is lighted the cover is put on and screwed to the lamp box in
the ordinary way. The toothed wheel formed on the inner side of the flange L
being turned has the effect of causing the toothed wheel C also to revolve, but when
the cover is being screwed on or fastened, the toothed wheel C is made to revolve
in such a way that the clutch upon D slides over the corresponding clutch affixed
to the spindle E¹ without causing the bevilled wheel E to revolve. When
however, an attempt is made to unscrew the cover of the lamp for the purpose of
removing it from the lamp box, the clutch on D catches the corresponding clutch
affixed to the spindle E' and causes the bevilled wheel E to revolve, which in its
turn causes the bevilled wheel F¹, the spindle F, and the skeleton drum G, all to
revolve. This has the effect of withdrawing the wick from the burner or wick
holder M, and of extinguishing the flame. It is thus impossible for any one using
the lamp to attempt to unscrew the cover from the lamp box without at once
extinguishing the light.
The only use of the sheath j shown on Figure 5 is to prevent the wick from
becoming entangled in the toothed wheels or other portion of the gearing.

page_text: Although in the Drawings the Davy lamp has been shown, my improvements can
be attached to any of the ordinary safety lamps used by miners, or any other safety
lamp.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that
I claim my improvements in miners' safety lamps, consisting in providing teeth
in connection with the upper portion or cover of the lamp, and a pinion in connec-
tion with the lower part thereof, so arranged that when the upper part is turned in.
detaching it from the lower part, motion is transmitted by the teeth and pinion to
an instrument which draws down the wick of the lamp and thereby extinguishes
the flame.
I also claim my improvements in miners' safety lamps, consisting in providing in
the lower part of the lamp, to receive and hold the wick, a frame or drum G which
when the upper part of the lamp is turned in detaching it from the lower part is
thereby made to rotate, and the wick being wound upon the frame or drum is
drawn down and the flame is extinguished.
:
I also claim my improvements herein: described in miners' safety lamps, or any
mere modification thereof.
In witness whereof, I, the said James Mason Douglas, have hereunto
set my hand and seal, this Twenty third day of February, in the year
of our Lord One thousand eight hundred and eighty.
JAMES M. DOUGLAS. (L.S.)