Year: 1886

page_text: We, WILLIAM JOHN CLAPP of Nantyglo, Surgeon and WILLIAM SANDBROOK of
Ebbw Vale, Ironmonger both in the county of Monmouth do hereby declare the
nature of said invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
The present invention relates to improvements upon an invention for which we
obtained provisional protection on June 3, 1885 N° 6727 and consists of a simple
arrangement and combination of parts for extinguishing the flame on a dangerous
heat being developed in the interior of the lamp.
According to our present invention we dispense with the extinguisher acting
directly on the flame and with its guides but we retain the extinguisher sur-
rounding the gauze chimney and we support the said extinguisher by means of a
central descending wire fixed to the cap or top thereof and resting upon a fusible
metal plug placed in a socket fixed in the centre of the top of the wire gauze
chimney, the said socket serves also as a guide for the wire of the extinguisher in
the descent of the latter after the fusible metal plug has been melted out of its
socket by the heat generated or developed in the interior of the lamp by tho
presence of gas.
We also fix in the interior of the outer casing or shield of the lamp a perforated
metal or it might be a wire gauze tube surrounding the extinguisher and serving
to prevent the falling of the extinguisher out of the shield or outer casing when
the latter is removed from the lamp whilst it also prevents the passage of small
coal dust to the gauze chimney.
We also fix over the flame a plate which is carried by a standard from the body
of the lamp and which serves to attract the flame and to protect the fusible plug
from the same.
.
Our invention is represented in the accompanying drawings in which Figure 1
is a vertical section of a safety lamp with our improvements applied thereto.
Figure 2 is a vertical section and Figure 3 is a sectional plan of the upper parts of
the lamp on the line 1, 1 of Figure 2; Figure 4 is an elevation and Figure 5 is a
plan of the shield or outer casing separately. Figure 6 is an elevation and
Figure 7 is a plan of the extinguisher separately.
In the various Figures like parts are marked with similar letters of reference.
a represents the body or reservoir of the lamp, b the burner and c the wick
trimmer; & is an annealed glass cylinder surrounding the burner and flame and

page_text: held between the metal rings or fittings ef, which are connected together by rods g
as is well understood.
The ring or fitting e screws on to the body or reservoir a or it may be secured
thereto by bayonet catches or by other suitable means and the ring or fitting ƒ has
the wire gauze chininey or cover fixed thereto.
In carrying our present invention into effect we fix at the centre of the top of
the wire gauze chimney ha socket ' in which we place a plug * of fusible metal
on which the extinguisher i is supported as shown at Figure 1 by means of a
wire fixed to such extinguisher and resting at its lower end on said fusible
plug the socket has shown at Figure 2 also acts as a guide to the wire i¹
after the fusible plug h³ has been melted out therefrom and a short tube or ring f¹
assists in guiding the extinguisher i on its descent; j is the outer casing or shield
which is perforated as shown or in other suitable manner for the ingress and egress
of air to and from the interior of the lamp; k is a perforated metal or it may be
wire gauze tube which is fixed at its lower end to the shield or outer casing j and
at its upper end acts as a support for the flanged head of the extinguisher i to
prevent the latter falling out from tho shield or outer casing j when the latter is
removed from the body a of the lamp; such tube also acts to prevent the small
coal dust from obtaining access to the wire gauze chimney h.
The shield or outer casing ; has projections or catches ¹ at its lower end which
act in combination with lugs or clips ffixed to the fitting f, in order to fix the
said shield or outer casing ; to the body of the lamp or said parts may be screwed
together.
is a plate fixed by a standard to the body or reservoir a; this plate is for
the purpose of attracting the flame and for preventing the heat of the same from
melting the fusible plug when gas is not present in the lamp.
The wick trimmer c is constructed as described in the complete specification of
our said former invention.
The upper part of the lamp is locked to the body or reservoir a by a stud or
bolt m in combination with a cross stud or bolt n and seal in a similar manner to
what is shown and described in our aforesaid complete specification except that the
head of the stud or bolt m is not enclosed in the lump e¹ but is exposed.
The shield or outer casing is also secured against surreptitious removal from the
lainp by means of a sliding rod or bolt gl which is secured in its locking position
by the studs or bolts m, n as described in our said specification.
The ring is also provided with holes f³ to admit air to the interior of the
shield or outer casing j.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is: —
The peculiar construction and combination of apparatus for automatically
extinguishing the flame of a safety lamp on a dangerous heat being developed or
generated within the body of the lamp and for preventing the flame of the lamp
from melting the fusible plug when gas is not present substantially as herein
shown and described.