IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY LAMPS FOR MINES
Year: 1867

page_text: LETTERS PATENT to Samuel Buxton and William Gardam, both of
Leeds, in the County of York, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF SAFETY LAMPS FOR MINES."
Sealed the 8th May 1868, and dated the 11th November 1867.
PROVISIONAL SPECIFICATION left by the said Samuel Buxton and
William Gardam at the Office of the Commissioners of Patents, with
their Petition, on the 11th November 1867.
We, SAMUEL BUXTON and WILLIAM GARDAM, both of Leeds, in the County
of York, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IT THE CONSTRUCTION OF SAFETY LAMPS FOR MINES," to be as follows:-
Our Invention has especial reference, in the first place, to the secure locking
of safety lamps, in order to prevent their being tampered with by the miners
using them, as is frequently the case with those in general use; and, secondly,
to the economy of time and of oil or substitute for oil effected by our arrange-
ment for connecting the lamp itself with its safety guard.
Our first object we accomplish in the following manner :-Within a
circular box (which contains the vessel carrying the oil or substitute for oil,

page_text: aud which forms the bottom portion of the lamp), we insert a vertical pin,
having its lower end screwed (by preference with a left-handed thread) and
accessible from the under side of the box by means of a key correspondingly
screwed inserted within the box. This key is formed with a shoulder, so that
when inserted in the bottom of the box, on being turned such shoulder may
press against the bottom and the key itself just catch the thread of the pin,
and so when turned draw it down. In doing this (as the upper end of the
pin projects slightly above the upper surface of the box and into a hole on
the under surface of the upper portion or guard of the lamp) the lamp is
unlocked, and by turning it round one-fourth of a circle (the upper or lower
portions of the lamp being connected by means of a bayonet coupling), the
safety part and the lamp part are detached. The economy of time and oil or
substitute for oil referred to arises from the manner in which the two portions
of the lamp are rejoined. The bayonet coupling referred to consists in
making two quadrants on the upper surface of the box, and two also on the
under surface of the safety part of the lamp. The latter quadrants being
passed between and underneath those on the box and then turned one-fourth
of a circle necessarily lock against the former quadrants, and they are kept in
that position by the vertical lock pin (before referred to), shooting when
released from the key by means of a spring into the hole made for it in the
under surface of the safety part. This reuniting of the top and bottom
portions of the lamp can be accomplished most expeditiously, and therefore it.
is not necessary for the lamp trimmer to light the lamps so early as is now
the case where many lights are used, owing to the screwing and locking
systems in vogue. It will thus be seen that it is practically next to impossible
for a miner to unlock his lamp, owing to the arrangement of the vertical pin
or lock, which requires a special key screwed internally, and having a shoulder
placed at a given accurate distance from the end.
The above-named improvements may be applied to the "Davy,"
"Stephenson," and other lamps in ordinary use.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Samuel Buxton and William Gardam, in the Great Seal
Patent Office on the 11th May 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, SAMUEL
BUXTON and WILLIAM GARDAM, both of Leeds, in the County of York, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of November, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto us, the said Samuel Buxton and William Gardam, Her special
licence that we, the said Samuel Buxton and William Gardam, our exe-
cutors, administrators, and assigns, or such others as we, the said Samuel
Buxton and William Gardam, our executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY LAMPS FOR MINES," upon
the condition (amongst others) that we, the said Samuel Buxton and William
Gardam, our executors or administrators, by an instrument in writing
under our or their hands and seals, or under the hand and seal. of one of. us
or them, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Gardam, on behalf of myself
and the said Samuel Buxton, do hereby declare the nature of the said
Invention, and in what manner the same is to be performed, to be parti-
cularly described and ascertained in and by the following statement thereof,
that is to say-
Our Invention has especial reference in the first place to the secure
locking of safety lamps in order to prevent their being tampered with by
the miners using them, as is frequently the case with those in general use;
and, secondly, to the economy of time and of oil or substitute for oil
effected by our arrangement for connecting the lamp itself with its safety
guard.
Our first object we accomplish in the following manner :-Within a circular

page_text: box (which contains the vessel carrying the oil or substitute for oil, and which
forms the bottom portion of the lamp) we insert a vertical pin, having its
lower end screwed (by preference with a left-handed thread) and accessible
from the under side of the box by means of a key correspondingly screwed
inserted within the box. This key is formed with a shoulder so that when
inserted in the bottom of the box on being turned such shoulder may press
against the bottom and the key itself just catch the thread of the pin, and
so when turned draw it down. In doing so (as the upper end of the pin
projects slightly above the upper surface of the box and into a hole on the
under surface of the upper portion or guard of the lamp) the lamp is un-
locked, and by turning it round one-fourth of a circle (the upper and lower
portions of the lamp being connected by means of a bayonet coupling) the
safety part and the lamp part are detached. The economy of time and oil or
substitute for oil referred to arises from the manner in which the two portions
of the lamp are rejoined. The bayonet coupling referred to consists in
making two quadrants on the upper surface of the box and two also on the
under surface of the safety part of the lamp, the latter quadrants being
passed between and underneath those on the box, and then turned one-fourth
of a circle necessarily lock against the former quadrants, and they are kept
in that position by the vertical lock pin (before referred to) shooting when
released from the key by means of a spring into the hole made for it in the
under surface of the safety part. This reuniting of the top and bottom portions
of the lamp can be accomplished most expeditiously, and therefore it is not
necessary for the lamp trimmer to light the lamps so early as is now the case
where many lights are used owing to the screwing and locking systems in
vogue. It will thus be seen that it is practically next to impossible for a
miner to unlock his lamp owing to the arrangement of the vertical pin or
lock which requires a special key screwed internally and having a shoulder
placed at a given accurate distance from the end. We find that the gauze
ring very often comes off from being insecurely attached, and to obviate this
defect we adopt a ring of copper or any other suitable metal spun or stamped
into the shape of the ordinary ring, except the flange is made as wide again
to allow of being turned over on to the wire gauze, the wire gauze being
previously turned outwards about an eighth of an inch, consequently when
the flange is turned over on to the gauze it cannot come off without bringing
the piece with it, making both the gauze and the ring much more durable
and at the same time saving a great deal of time, trouble, and expense. And
again we find that lamps made of brass are soon broken from the softness of
tle metal. To obviate this difficulty we prefer to use malleable iron, being a

page_text: much more suitable and harder metal not liable to verdigris, consequently
being more lasting and cheaper.
The above-named improvements may be applied to the "Davey," "Stephen-
son," and other lamps ordinarily used.
In order, however, that our Invention may be the better understood
reference is made to the accompanying Sheet of Drawings, and to the letters
and figures marked thereon, that is to say :-
DESCRIPTION OF DRAWINGS.
Figure 1 is a front elevation; Figure 2 is a vertical section; Figure 3 an
underneath view of the upper part of the lamp; Figure 4 is a plan view of
the bottom part of the lamp.
By reference to Figure 2 and the letters marked thereon, a shows the
passage through which the key is introduced to the screwed pin b. It will be
observed that the collar c which is screwed into the oil receiver is merely
introduced for the sake of forming a separation between the oil holder and
the pin part, and at the same time to keep the pin and spring in their place.
Immediately upon the application of the key, Figures 5 and 6, to the lower
end of the pin b, Figure 2, the latter is drawn downwards, and the part d
free to be moved a quarter of a circle, which unlocks the bayonet guard e,
Figure 4, and ¹, Figure 8. When it is desired to close the lamp it is simply
necessary to place the top part on the bottom part and turn it one-fourth of
a circle as before, the consequence being that the lock or bolt 6 shoots into
the recess formed for it in d, by the assistance of the spring f, and is pre-
vented from twisting by a groove cut in the collar 6', or by making the top
of the pin square working in a square hole in the lamp or by a vertical groove
in the shoulder b¹ of the pin b. The remainder of the lamp may be of any
pattern.
Having now stated the nature of our Invention, and in what manner the
same may be performed, we wish it to be understood that what we claim is,―
Firstly. A shooting bolt working with a spring, and to withdraw the same
we prefer to use a screwed key, screwed either internally or externally, but
by preference internally, and by preference with a left-hand thread, and
having its fulcrum by means of a shoulder larger than the hole a upon the
bottom of the oil receiver A, and the allowing of the pin's return when the
top and bottom parts are put together, by the self-action of the spring f
upon the pin b.
And, secondly. The mode of attachment between the top and bottom parts
of the lamp by the use of bayonet joints.

page_text: And, thirdly. The mode of attaching the gauze to the ring in the manner
before explained.
And, fourthly. The use of malleable iron for the purpose before explained.
In witness whereof, I, the said William Gardam, have hereunto set my
hand and seal, this Ninth day of May, in the year of our Lord
One thousand eight hundred and sixty-eight.
Witness,
J. W. BULMER,
Clerk of P. H. Sharp,
Leeds.
WILLIAM GARDAM. (L.B.)