IMPROVEMENTS IN MINER'S SAFETY LAMPS
Year: 1886

page_text: Date of Application, 27th Mar., 1886.
Complete Left, 24th Dec., 1886.
Complete Accepted, 25th Jan., 1887
RESERV
1 ANDREW HOWAT, of 65 Bristol Street, Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of said Invention for IMPROVEMENTS IN
MINER'S SAFETY LAMPS to be as follows:-
:-
The chief object of my Invention is to dispense with the use of the "Davy" lamp
now generally employed by the firemen in mines for the purpose of trying or testing
the workings in order to ascertain whether any explosive gas is present.
I accomplish this object by altering the construction of certain classes of safety
lamps so as to adapt thein for this particular purpose.
In applying my invention to a safety lamp in which the wire gauze cylinder (or
cylinders) is covered with a metal shield or casing and which is provided with a
deflector made according to the Invention for which I applied for Letters Patent
No. 1709 on the 5th February 1886, I provide means whereby the ordinary air inlet
can be opened or closed at will, a convenient method of effecting this being to fit the
shield on the lamp frame in such manner that by simply turning or moving the shield
the air inlet is opened or closed, a set screw or other device being employed to fix the
shield in position. I admit the air to be tried or tested through a tube the upper end
of which is or may be funnel shaped terminating rather above the top of the lamp and
the lower end is connected to the lamp, preferably to the metal shield at a point
slightly below the level of the deflector. When the ordinary air inlet is closed all the
air for combustion is admitted to the lamp through this tube and if any gas is admitted
its presence will be readily detected.
When the lamp is to be used for ordinary lighting purposes the funnel shaped tube
may be detached and air for combustion admitted through the ordinary inlet.

page_text: I ANDREW HOWAT of 65 Bristol Street, Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of said Invention for IMPROVEMENTS IN
MINERS SAFETY LAMPS, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
The chief object of my Invention is to dispense with the use of the "Davy" lamp
now generally employed by the firemen in mines for the purpose of trying or testing
the workings in order to ascertain whether any explosive gas is present.
I accomplish this object by altering the construction of certain classes of safety
lamps so as to adapt them for this particular purpose.
In applying my Invention to a safety lamp in which the wire gauze cylinder (or
cylinders) is covered with a metal shield or casing and which is provided with a
deflector made according to the Invention for which I obtained Letters Patent
No. 1709 dated the 5th February 1886 I provide means whereby the ordinary air inlet
can be opened or closed at will, a convenient method of effecting this being to fit the
shield on the lamp frame in such manner that by simply turning or moving the shield
the air inlet is opened or closed a set screw or other device being employed to fix the
shield in position. I admit the air to be tried or tested through a tube the
upper end
of which is or may be funnel shaped terminating rather above the top of the lamp and
the lower end is connected to the lamp preferably to the metal shield at a point slightly
below the level of the deflector. When the ordinary air inlet is closed all the air for
combustion is admitted to the lamp through this tube and if any gas is admitted its
presence will be readily detected.
When the lamp is to be used for ordinary lighting purposes the funnel shaped tube
may be detached and air for combustion admitted through the ordinary inlet.
And in order that my Invention may be fully understood and readily carried into
effect I will describe the accompanying two Sheets of Drawings, reference being had
to the figures and letters marked thereon.
Similar letters refer to similar parts throughout the several views.
Figures 1 to 5 show a miners safety lamp of the type previously mentioned and
embodying my present Invention.
This lamp has a metal shield a which in this arrangement is fitted and free to turn
on the lamp frame & the shield being secured in position by screws c passing through
the frame band entering slots a¹ in the shield a. At the base of the shield a is an
internal annular flange a see Figure 3 which is cut away at intervals corresponding
with the air inlet openings 6 see Figure 5 formed in the lamp frame b; d is the
deflector which is secured to the rods e and is made and arranged as described in my
said Patent No. 1709 of 1886; fis the funnel which is screwed on to a tube f¹ secured
to the shield a; g is the outer gauze cylinder; h the glass and the burner of
the lamp.
When the lamp is used for the purpose of testing the workings the ordinary inlet
openings are closed by simply turning the shield a so as to bring over them the
solid parts of the flange a' the shield a can then be secured in place to keep it from

page_text: turning back by the thumb screw c¹. When the openings are closed in this manner
all the air admitted for combustion must enter the lamp through the funnel f and if
any gas be admitted its presence will be readily detected. If required to extinguish
the lamp this may be almost instantaneously effected by placing the hand on the
mouth of the funnel f.
When not used for testing purposes the funnel can be removed and air for
combustion admitted to the lamp through the ordinary inlet openings b¹.
It is obvious that the air openings might be placed horizontally in the side of the
frame and the movable shield instead of vertically as shown and described and that
various other arrangements for opening and closing the air inlets may be employed;
also instead of the shield being movable it may be fixed to the lamp frame or a
loose
shield may be used in combination with a locking device as set forth in my previously
mentioned Patent No. 1709 of 1886.
Figures 6 to 8 show a similar lamp to that already described with reference to
Figures 1 to 5 but in this case the shield a is fixed at 2 to the lamp frame b instead
of being movable and the air openings are made horizontally in the side of the
frame instead of vertically as in the previous arrangement Figures 1 to 5.
A split ring in which are a series of slots ¹ corresponding to the openings b² is
fitted in an annular groove in the frame 6 over the said openings so that by turning
the ring the ordinary inlet for air can be closed and all the air for combustion can be
adinitted through the funnel in the manner and for the purposes already described.
Figure 9 illustrates one mode of employing a loose shield in combination with a
locking device at the top of the lamp.
In this case the locking device consists of a projection / formed on the top plate l
and through a hole in this projection is passed a lead rivet m the end of which is
then flattened so that the shield a cannot be removed without first cutting off one of
the ends of the rivet. Instead of the lead rivet a screw or any other suitable seal may
be employed to lock the shield and prevent it from being removed without detection."
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is-
1. In a safety lamp the combination with means for closing the ordinary air inlet,
of means such as the funnel shaped tube f for supplying preferably from above the top
of the lamp a small quantity of air for combustion substantially as and for the purposes
herein described and as illustrated by the accompanying Drawings.
2. In a safety lamp the combination with the shield a deflector d and means for
closing the ordinary air inlet, of a special inlet for introducing at a point below the
said deflector a small quantity of air for combustion drawn from a point preferably
above the top of the lamp substantially as herein set forth for the purpose specified.
3. The combination with the ordinary air openings 6 of the movable shield a
provided with an annular flange a² and a separate inlet for air substantially as herein
described with reference to Figures 1 to 5.
4. The combination with the shield a provided with a special air inlet and either
fixed to the lamp frame or secured to it by a locking device, of means such as the
ring of closing the ordinary air openings substantially as herein described with
reference to Figures 6 to 9.
5. The several constructions combinations and arrangements of parts constituting
my improvements in miners safety lamps substantially as herein shown and described.
H. B. BARLOW,
17, St. Ann's Square, Manchester,
Agent for Applicant.