An Improvement in the Construction of Certain Miners' Safety Lamps.
Year: 1889

page_text: Date of Application, 2nd Nov., 1889
Complete Specification Left, 23rd Apr., 1890-Accepted, 24th May, 1890
PROVISIONAL SPECIFICATION.
An Improvement in the Construction of Certain Miners' Safety
Lamps.
I, ANDREW HOWAT, of 6 Bellwood Terrace, Old Trafford, Manchester in the
County of Lancaster, Engineer, do hereby declare the nature of this invention to be
as follows:-
.
My invention relates to an improvement in the construction of those miners'
safety lamps now generally known as "Deflector" Lamps that is to say a bonneted
lamp with a gauze cylinder or cylinders having the air inlet above the glass and.
fitted with a deflector in the manner set forth in the Specification to Letters Patent
No. 1709 of 1886 granted to me.
In such a lamp having a loose or detachable outer metal shield or bonnet and
with the deflector fixed upon the rods of the lamp frame there is a possibility of
the deflector getting displaced accidentally or otherwise during repairs etc., in which
case there would probably be a bad fit between the bonnet and the deflector and
some air might be able to escape unconsumed through the outlet at or near the top
of the bonnet. Again the same thing would happen if the bonnet were not properly
pressed down into the recess formed for its reception in the horizontal ring of the
lamp frame above the glass even if the deflector in this case remained in its proper
position.
The chief object of my present improvement is to prevent any possibility of the
deflector getting displaced and to so arrange the bonnet that it cannot materially affect
the amount of air supplied to the flame.
In carrying out this improvement I construct an air chamber the bottom of which
is, formed by the horizontal ring of the lamp frame above referred to, the outer side
by a metal ring or short cylinder formed with or secured to the horizontal ring, and
the top by the deflector which is secured to or formed with the outer side. If a
high vertical collar be employed as recommended by the Royal Commissioners on
Accidents in Mines in their Final Report of March 1886 then this collar forms
the inner wall of the air chamber and is formed with or fixed to the aforesaid
horizontal ring.
In practice I propose to cast the high vertical collar in one piece with the
horizontal ring and the deflector in one piece with the outer wall and then secure. the
two pieces together to form a chamber as above described.
1 fit the bonnet which is of course shorter than heretofore, in a groove or recess
above the deflector and when a loose bonnet is employed I secure it in position by
any suitable locking device.
:
Dated thin and L 1000
COMPLETE SPECIFICATION.
An Improvement in the Construction of Certain Miners' Safety
Lamps.
I, ANDREW HOWAT, of 6 Bellwood Terrace, Old Trafford, Manchester, in the County
of Lancaster, Engineer, do hereby declare the nature of this said invention and in
what manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
:-
My invention relates to an improvement in the construction of those miners' safety
lamps now generally known as "Deflector" Lamps that is to say a bonneted lamp

page_text: with a gauze cylinder or cylinders having the air inlet above the glass and fitted
with a deflector in the manner set forth in the Specification to Letters Patent No. 1709
of 1886 granted to me.
In such a lamp having a loose or detachable outer metal shield or bonnet and
with the deflector fixed upon the rods of the lamp frame there is a possibility of the
deflector getting displaced accidentally or otherwise during repairs &c., in which
case there would probably be a bad fit between the bonnet and the deflector and some
of the air admitted to the annular space between the bonnet and the gauze cylinder
might be able to flow upward and to escape unconsumed through the outlet at or
near the top of the bonnet without first passing through the gauze into the burner
chamber. Again the same thing would happen if the bonnet were not properly
pressed down into the recess formed for its reception in the horizontal ring of the
lamp frame above the glass even if the deflector in this case remained in its proper
position.
The chief object of my present improvement is to prevent any possibility of the
deflector getting displaced and to so arrange the bonnet that it cannot materially affect
the amount of air supplied to the flame.
In carrying out this improvement I construct an air chamber the bottom of which is
formed by the horizontal ring of the lamp frame above referred to, the outer side by a
metal ring or short cylinder formed with or secured to the horizontal ring, and the top
by the deflector which is secured to or formed with the outer side. If a high vertical
collar be employed as recommended by the Royal Commissioners on Accidents in
Mines in their Final Report of March 1886 then this collar forms the inner wall of
the air chainber and is formed with or fixed to the aforesaid horizontal ring.
And in order that my invention may be fully understood and readily carried into
effect I have hereunto annexed a Sheet of Drawings, in which
Figure 1 is an elevation of a "Deflector" miners' safety lamp embodying my
present improvement.
Figure 2 is a sectional elevation of the same with the bonnet or metal shield
removed.
Figures 3 and 4 are plan views taken respectively on the planes of the
lines A B, C D.
The lamp illustrated in the Drawings is shown with two gauze cylinders a a¹ sur-
mounting the glass b which encloses the burner c.
The reservoir for the oil or other illuminant is connected to the horizontal ring d
of the lamp frame by rods e and the top plate f of the lamp is carried by the
rods e which pass through the deflector g and are secured to the top plate fand to
the ring d.
It will be clearly seen on reference to Fig. 2 that the sides of the air chamber H
are formed by the outer ring or cylinder i, the high inner vertical ring or collar k,
and the top of the said chamber by the deflector g and the bottom by the horizontal
ring d.
In practice I propose to cast the high vertical collar.k in one piece with the
horizontal ring d which is provided as usual with air inlets d' and the deflector.g in
one piece with the outer wall or ring i and then secure the two pieces together to
form the chamber H above described, but it will be obvious to any practical man
acquainted with the manufacture of miners' safety lamps that this forination of the
air chamber H might be slightly varied or modified without departing from the nature
of my invention.
The joint between these two said pieces may be formed by spinning the metal over
or by soldering them together or in any other convenient and suitable manner.
I fit the bonnet or outer metal shield m which is of course shorter than here-
tofore in lamps of this class, in a groove or recess g³ above the deflector g and when
a loose bonnet is employed I secure it in position by any suitable locking device.
In Fig. 1 of the Drawings a simple form of lead rivet lock o is shown for this
purpose; but I do not wish to confine myself to that or to any other mode of
locking, the bonnet. The air inlets d¹ are shown formed in the horizontal ring d

page_text: but when the high vertical collar & is employed as shown the air inlets may be
formed instead or in addition in the outer wall or ring i just above the horizontal
ring d.
My present improvement is shown applied to a lamp of the Marsaut or bonneted
Clanny type with two gauze cylinders and no chimney but it may also be applied to
lamps of the bonneted Mueseler type.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed
1. In a miners' safety lamp of the type specified the improvement which consists
essentially in forming or combining the deflector with the air chamber as an
integral portion thereof substantially in the manner and for the purposes herein set
forth.
2. The air chamber H constructed and arranged as and for the purposes herein
set forth.
Dated this 22nd day of Anril 1890.
H. B. BARLOW,
17, St. Ann's Square, Manchester, Agent for Applicant.