IMPROVEMENTS IN SAFETY OR MINERS' LAMPS."
Year: 1880

page_text: LETTERS PATENT to Frederick Leech Leech, of Cheetham Hill, in the County
of Lancaster, Joseph Thomas Leech, of Pendleton, in the same County, and
James Hardman, also of Pendleton, for an Invention of "IMPROVEMENTS IN
SAFETY OR MINERS' LAMPS."
PROVISIONAL SPECIFICATION left by the said Frederick Leech Leech,
Joseph Thomas Leech, and James Hardman, at the Office of the Commissioners
of Patents on the 31st January 1880.
FREDERICK LEECH LEECH, of Cheetham Hill, in the County of Lancaster,
JOSEPH THOMAS LEECH, of Pendleton, in the same County, and JAMES HARDMAN,
also of Pendleton. IMPROVEMENTS IN SAFETY OR MINERS' LAMPS."
"
Our Invention relates to the safety lamps which are adapted for use in coal
mines or in other mines or places wherein there is liability for the air to be
explosive, as is well understood, and the object of our Invention is to provide that
the said lamps cannot be opened without by so doing extinguishing the light. To
this end we, in the first place, surround the wick tube with a ring or part which
passes into position in the upper part of the lamp when the two parts are put
together, but is left in the upper part when the lower part or lamp bottom is with-
drawn, whereby the light is extinguished by being drawn through the said ring
or part. In a lamp having the lower part or bottom arranged to screw into the
upper part the said ring is also formed to screw into the upper part, the two screw
threads corresponding, so that when the lamp bottom is screwed to the upper part
the said ring at the same time screws into its seating. When the lamp bottom is
unscrewed the wick tube is withdrawn through an opening in the said ring, which
remains in its seating, or through a tube attached to the said ring, and the light
becomes extinguished. Teeth or projections on the lamp bottom and on the said
ring engage when the parts are put together, but clear each other when the lamp
bottom is unscrewed. In the second place we employ a hinged cover in one or
two parts, which can be thrown back over the aforesaid ring when the said ring is
placed in position on or around the wick tube. When the lamp bottom is
unscrewed, the said hinged cover or covers cannot pass through the said ring until
it or they have become folded or moved into position over the wick, whereby the
wick becomes extinguished.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederick Leech Leech, Joseph Thomas Leech, and James
Hardman, in the Great Seal Patent Office on the 29th July 1880.
FREDERICK LEECH LEECH, of Cheetham Hill, in the County of Lancaster,
JOSEPH THOMAS LEECH, of Pendleton, in the same County, and JAMES HARDMAN,
also of Pendleton. " IMPROVEMENTS IN SAFETY OR MINER'S LAMPS."
Our Invention relates to the safety lamps which are adapted for use in coal
mines or in other mines or places wherein there is a liability for the air to be
explosive, as is well understood, and the object of our Invention is to prevent the
opening of the lamp without thereby extinguishing the light. To this end we, in
the first place, surround the wick tube with a ring or part which passes into
position in the upper part of the lamp when the two parts are put together, but
is left in the upper part when the lower part or lamp bottom is withdrawn, whereby
the light is extinguished by being drawn through the said ring or part. In a lamp
having the lower part or bottom arranged to screw into the upper part the two
screw threads correspond, so that when the lamp bottom is screwed to the upper
part the said ring at the same time screws into its seating. When the lamp bottom
is unscrewed the wick tube is withdrawn through an opening in the said ring,
which remains in its seating, or through a tube attached to the said ring, and the
light becomes extinguished. Teeth or projections on the lamp bottom and on the
said ring engage when the parts are put together, but clear each other when the
lamp bottom is unscrewed. In the second place we employ a hinged cover in one
or two parts, which can be thrown back over the aforesaid ring when the said
ring is placed in position on or around the wick tube. When the lamp bottom is
unscrewed the said hinged cover or covers cannot pass through the said ring until
it or they have become folded or moved into position over the wick tube, whereby
the light becomes extinguished.
And in order that our Invention may be fully understood, we have attached
hereunto a Sheet of Drawings marked with letters of reference, to which Drawings
we will refer in this place. Fig. 1, partly in section, represents a complete safety
lamp and illustrates the second part of our Invention. In the said Fig. a is the
lamp proper or lamp bottom, which is formed with a screw thread a¹, whereby it
is screwed into a ring b which forms the basis of the lamp cover, that is to say, of
the upper part of the lamp. The said cover may be of any suitable form and con-
struction. In the example the framing of the said cover encloses a glass cylinder c
and a cylinder d of wire gauze. We prefer to add an inner lining or outer casing
of spirally coiled wire to the said gauze cylinder. A short length of such lining is
represented by Fig. 7. Upon the ring b a pap or hollow boss e is formed, and in
the interior of this pap is formed a screw thread which is of the same pitch as the
screw thread a¹. A ring f is formed to screw into the said pap. According to the
first part of our Invention this ring is formed with a central passage through which
the wick tube g projects, as indicated in Fig. 1ª. Preparatory to the screwing into
position of the lamp bottom the ring f is slipped over the tube g so as to rest
upon a collar h which projects from the lamp bottom. A alightly projecting tooth
is formed upon the upper surface of the collar h, and a corresponding tooth is
formed upon the lower side of the ring f, as indicated in Fig. 1ª. There is a
corresponding formation in the example illustrated by Fig. 1. When the parts
are being screwed together the ring fenters the pap e, and the said teeth engaging
together the said ring is screwed upwards into the pap by the rotatory movement
of the lamp bottom, and the screw threads a¹ engaging with the interior thread in
the ring 6 the lamp bottom becomes screwed to the lamp cover. When the lamp
bottom is turned in a contrary direction in the act of unscrewing it from the cover
the tooth on the collar h moves away from the tooth on the ring f, and therefore
the latter does not rotate with the lamp bottom. By the time the lamp bottom
has made a complete revolution the tooth on the said collar has become lowered to

page_text: the extent of the pitch of the screw-thread, and therefore clears the other tooth at
the second turn, and the ring f continues stationary whilst the lamp bottom is
unscrewed and removed. It will be seen that during the unscrewing and removal
of the lamp bottom the upper end of the wick-tube, and as a consequence the
flame arising from the wick, passes into the interior of the ring, the said flame
thereby becoming extinguished. As the lamp bottom cannot be removed without
the flame so passing into the ring the extinguishment of the flame is inseparable
from the action of removing the said lamp bottom, that is to say, of "opening the
lamp." In Fig. 1 an extinguisher formed in two parts i, i, is hinged to the wick
tube; Fig. 4 is an inner view of one of the said parts. When the lamp is in use
the parts of the said extinguisher hang away from the flame, as seen in Fig. 1.
When the lamp bottom is unscrewed the ring f remains stationary, and by the
descent of the wick tube the parts of the extinguisher by coming in contact with
the said ring are folded together over the flame in the manner indicated in Fig. 2,
and the flame thereby becomes extinguished. The passage through the ring is
formed with two recesses, as indicated in Fig. 3, which is a plan of the said ring.
When the wick tube is drawn down the hinged ends of the parts i enter the said
recesses and act as a key, whereby the said ring is turned in order that it may be
unscrewed out of the pap e; Figs. 5 and 6 illustrate a modification in the form
and action of the extinguisher. In this example a flap k is hinged to the wick
tube, and is acted upon by a coiled spring upon the hinge pin, or by a spring
otherwise suitably arranged in such a manner as that the said flap tends to move
into position to cover the top of the wick tube, and thereby to extinguish the flame.
A hook or link l attached to the ring fholds back the flap during the screwing
together of the parts of the lamp, and also during the subsequent use of the lamp.
When the lamp bottom is unscrewed the said flap moves away from the link l, and
the flap then turns over so as to cover the end of the wick tube, and thereby
extinguishes the flame. The forms of the extinguisher or extinguishers, and of the
ring or part f, may be varied without departing from the nature and intent of our
Invention.
Having now fully set forth and indicated the nature of our said Invention, and
the manner in which we carry the same into practical effect, we would have it to
be understood in conclusion that we claim,―
First. The combination of parts forming a complete safety lamp, substantially
as set forth and indicated hereinbefore, and in and by the accompanying
Drawings.
Secondly. The ring or extinguisher arranged to screw into a seating when the
lamp is being closed, and to remain stationary in such seating when the lamp is
opened, substantially as and for the purpose set forth and indicated.
And, lastly. The hinged extinguisher or extinguishers acting in concert with a
ring or part f, substantially as and for the purpose set forth and indicated.
In witness whereof, I, the said Frederick Leech Leech, for myself and on
behalf of the said Joseph Thomas Leech and James Hardman, have hereunto
set ny hand and seal, this Twenty-eighth day of July, in the year of
our Lord One thousand eight hundred and eighty.
Witness,
EDWARD K. DUTTON,
41, John Dalton St.,
Manchester.
FREDERICK LEECH LEECH. (L.S.)