AN IMPROVED "DAVY" SAFETY LAMP
Year: 1885

page_text: I, ROBERT WRIGHTSON SEDGWICK, of Murton Colliery, near Sunderland, in the
County of Durham, Mining Engineer, do hereby declare the nature of my invention
for AN IMPROVED "DAVY" SAFETY LAMP to be as follows:—
The peculiarity of this invention consists in the method adopted for attaching
the well known chimney, or "can," as it is termed by the miners, which is a metal
cylinder having a portion of its surface formed of glass, and which cylinder is
placed outside the wire gauze chimney of the "Davy" lamp.
In my improved lamp two angular knees or lugs are attached to the lower end
of the "can," which knees fit into recesses made in the body of the lamp to receive
them, in such manner that when the bottom, or oil chamber of the lamp, is screwed
into, or on to, the upper part or gauze chimney, the said knees are firmly held
"between the two portions of the lamp, and no further fastening is necessary to
secure the "can.” The result is greater simplicity and increased convenience in
managing the lamp, and the dispensing with the ordinary system of employing a
separate locking arrangement to secure the said "can." In my improved lamp the
glass portion may form a part or the whole of the circumference of the "can
as preferred, and the aforesaid "can may, if desired, be shortened so as to surround
the flame only and not the whole upper portion of the lamp.
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page_text: for
I, ROBERT WRIGHTSON SEDGWICK, of Murton Colliery, near Sunderland, in the
County of Durham, Mining Engineer, do hereby declare the nature of my invention
AN IMPROVED "DAVY" SAFETY LAMP," and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
دو
The well known "Davy" safety lamp for miners, is now for weighty reasons
generally enclosed when in use in an additional case or "chimney
or as it is
termed by the miners a "can" which surrounds the gauze wire inside of which
the wick of the lanp is burning.
These "cans" are slipped over the top of the lamp and as it is necessary to
prevent their removal by the miners, they are usually furnished with a separate
locking arrangement.
The "Davy" lamp consists of two main parts viz, the oil holder, and the gauze
chimney and metal top.
These two parts are usually screwed together at the point of juncture, where
is a recess or waist, and when. screwed together are, fastened by a screw-lock or
other suitable fastening..
In my improved lamp, the outside chimney or "can." instead of descending over
the gauze chimney in the usual way and being fastened separately, is furnished
with knees or lugs or a rim or flange, projecting inwards, at the lower end, or any
similar attachment or device, such as a screw or bayonet joint, to engage with and
fasten against the waist of the lamp or with notches or a thread or studs formed in
the frame of the lamp in such a manner that the said chimney cannot be drawn
upwards over the gauze chimney, nor can it be removed from the lamp until the
lamp itself is unscrewed and detached..
It is therefore obvious that no separate fastening is needed, but the lock of the
lamp is sufficient to secure the chimney.
My improved chimney may be constructed with its centre circumference formed
wholly or in part of glass as required, and may be carried to the summit of the
lamp, or only to the top of the gauze chimney as preferred.
"
"
"
In the accompanying drawings, Figure 1. represents an elevation of one form of
my improved chimney" or "can' as designed to form the exterior of the "Davy
lamp, and is constructed with a cylindrical glass body extending entirely around
the flame of the lamp, and also with a circular metal flange (D) curved inwards at
the lower end to secure it to the lamp.
Figure 2 shews a section of this "chimney" or "can" with the flange D plainly
visible.
Figure, 3-shews a section of another form of my improved "chimney" or "can,"
in which lugs or knees (E) are used to secure the chimney to the lamp. In this
form of chimney only about one-third of the circumference is usually of glass,
the remaining two-thirds being metal, to the lower end of which the lugs are
attached.
Similar letters denote similar parts throughout.
A. is the upper portion of the chimney and is formed of metal.
T

page_text: C. is an annular base or frame attached to A by wires which traverse the glass
body, or connected thereto in some other suitable manner.
D. is the interior flange, and
E. is one of the lugs before described.
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
"
66 can fitted with
1. An improved "Davy" lamp having an external chimney or
an internal flange or with lugs, or other interior fitting, so as to engage with
recesses studs or other corresponding fittings on the lamp and firmly secure the
said chimney without any external fastening.
"
2. An external chimney or "can for a "Davy' lamp which is self-locking and
cannot be removed without first unlocking and opening the lamp.
Dated this 2nd day of November 1885.
S. S. BROMHEAD,
Patent Agent,
97, Newgate Street, London, E.C.