IMPROVEMENTS IN APPARATUS APPLICABLE TO MINERS' CARRENTLY LAW
Year: 1879

page_text: LETTERS PATENT to William Purdy, of Eastwood, in the County of Nottingham,
for the Invention of "IMPROVEMENTS IN APPARATUS APPLICABLE TO MINERS'
CARRENTLY LAW"
Sealed the 24th June 1879, and dated the 10th April 1879.
PROVISIONAL SPECIFICATION left by the said William Pardy at the Office
of the Commissioners of Patents on the 10th April 1879.
WILLIAM PURDY, of Eastwood, in the County of Nottingham.
IN APPARATUS APPLICABLE TO MINERS' SAFETY LAMPS."
"
IMPROVEMENTS
Instead of employing a gauze cylinder or cylinders as heretofore, I secure a
metal shell above the glass of a miner's lamp. I also employ a glass somewhat
longer than those heretofore used, and above the glass within the shell I place a
perforated metal rim or cylinder having a horizontal perforated plate or top, above
which is a rim and plate of gauze, the whole secured in the shell by a screwed ferrule,
and above these the shell is perforated sufficiently to readily allow of the escape of
the heated air, and on the top of the shell is an arched or other shaped shield
provided with a ring and swivel of the usual construction. The gallery carrying
the glass is secured to the shell by means of two or more vertical rods. Below the
glass I secure a gauze rim or cylinder lining the neck of the gallery, which neck is
drilled full of holes, each of which incline downward from the outside to the inside,
and below the neck of the gallery I secure the reservoir and the lamp, which is
The lamp is
tapered upwards to make room for the gauze lining before named.
provided with a flattened tube to carry a flat wick, which is secured in place by a
pin and spring. To effectually lock the lamp when closed, I drill or otherwise form
a hole on the underside of the lower rim of the gallery, to receive a bolt, which is
pressed into it by a spring, which is coiled on its stem below a disc forming part
of the belt, which slides in a chamber provided for it in the thickness of the side
of the reservoir.
Below the spring or at the side of it I form a suitable shaped air way, through
which I exhaust the air below the disc of the locking bolt, producing a vacuum,
thereby causing the bolt to descend to enable the lamp to be unscrewed for
relighting, cleaning, or other purpose; the air may be exhausted by means of any
suitably constructed pneumatic instrument.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Purdy in the Great Seal Patent Office on the 10th October
1879.
WILLIAM PURDY, of Eastwood, in the County of Nottingham.
IN APPARATUS APPLICABLE TO MINERS' SAFETY LAMPS."
"IMPROVEMENTS
In carrying out my improvements I employ several modifications as follows :-
1st. I secure what I term a metallic-dome, consisting of a cylinder or cylinders,
shell or shells, instead of as heretofore a gauze.
2nd. An iron or other metallic tube passing up the said dome secured in the
neck thereof by a threaded ferrule or otherwise. On the top of this inner tube is
fitted a copper perforated plate, over which passes a gauze cap fitted on the top of
the tube, the mesh of the gauze being as required by the Miners' Act of 1872.
3rd. A row of holes is formed round the top of the dome to readily allow the
heated air to escape after passing through the gauze cap.
4th. The gallery beneath is secured by pillars, inside which the glass is fitted.
5th. Small air holes are bored round the gallery into a hollow rim, in which is
fitted a gauze drum on a threaded ferrule, which secures the glass up to the dome,
and is so arranged as to fit and face the interior of the air holes, through which the
air passes to feed the flame.
6th. The reservoir is screwed in the neck of the gallery by male and female
screws. The reservoir has a pricker passing through and working in a small tube
to raise and lower the wick in a flat or round burner, and so arranged as to burn
any kind of mineral or vegetable oil.
7th. For the locking of the lamp I secure a cylinder bored out of the brass cast
inside the vessel, or otherwise secured thereto, in which moves a piston having a
piston rod or bolt passing up the cylinder and projecting above the rim on the
vessel, and held up by a spiral or other spring; same is fitted on a recess in the
cylinder. The spring holds the piston rod up, and the lamp being screwed on,
gradually holds the rod down on the spring for the last revolution until it is forced
up by the spring into the recess in the gallery, which is prepared to receive it, and
thus locks the lamp perfectly safe.
8th. Near the bottom of the lamp is a button projecting on the side of the vessel
having a hollow screw, and bulged or studded on the inside so as not to be taken
out. A small hole is bored into this hollow screw from the outside, which, when
the button is screwed up to the lamp side, carries the air hole to inside the brass,
and when released, allow the air-hole to be accessible for the purpose of exhausting
the air through with the pump.
9th. For unlocking the lamp I secure a pneumatic pump with one or more valves
worked by a lever or otherwise, having a cup near the bottom faced with india-rubber
or cork, to form an air-tight joint to side of the lamp, as the hollow screw, being
released a little, allows the air hole to be accessible, and this being held in the cup
or mouth of the pump by a lever, screw, or otherwise, the air is exhausted by the
pump out of the cylinder, and forms a vacuum under the piston, and the atmo-
spheric pressure forces down the piston into the vacuum, and thus brings down the
rod or bolt lower than the recess, and allows the lamp to be screwed off for cleaning,
relighting, replenishing, etc.

page_text: C is a copper perforated plate on the top of the tube.
G, gauze cap fitted over the perforated plate.
Gis a glass fitted to the bottom of the said dome and top of the gallery.
O¹, O¹, is a gallery secured to the said dome by pillars, inside which is fitted a
gauze drum, which secures the glass.
H, H, small air holes, through which the air passes into the hollow rim O, O,
and passes through the gauze drum D¹, D¹; V is the vessel which contains com-
bustible liquid or light supplier; P is the pricker passing through a tubet for
raising and lowering the wick in a flat or round tube; F is a flange to secure
top of the glass; C' is a cylinder inside the vessel; P¹ is a piston; N, piston rod
projecting above the rim of the vessel; S is a spring resting on a recess r; M is a
hole in the gallery to receive the rod or bolt; X, hollow screw studded on the
inside and having a button B on the outside for the purpose of releasing the air
hole E, and bringing it to the outside of the cylinder (Fig. 2); P2, P², (Fig. 2), is a
pneumatic pump for exhausting the air from the cylinder of the lamp for the
purpose of unlocking it, being held tightly into the cup or mouth of the pump M;
P³ is the piston of pump; V₁ is the valve; R¹ is an india-rubber band.
Having now particularly described and ascertained the nature of the said Inven-
tion, and in what manner the same is to be performed or put in practice, I hereby
declare that I claim the Invention of "Improvements in Apparatus Applicable to
Miners' Safety Lamps," substantially as saine is hereinbefore set forth and described,
in which Invention the important points or features are the adoption of what I
term the dome, that is, a nonperforated but hollow cylinder and top, with tube,
perforated plate, and gauze cap, so combined and used with other necessary subsidiary
arrangements (such as have been hereinbefore referred to and explained) that my said
Invention as hereinbefore described may be carried out in practice, it being under-
stood that I do not limit myself to the precise details shewn by the Drawings and
described with reference thereto, as the same might be varied without departing
from the essential features of my said Invention.
In witness whereof, I, the said William Purdy, have hereunto set my hand
and seal, this Eighth day of October, in the year of our Lord One
thousand eight hundred and seventy nine.
Witness,
WILLIAM TOWNSEND,
Eastwood,
Notts.
WILLIAM PURDY (Miner). (L.S.)