Improvements in Miners' Safety Lamps, which Improvements are partly applicable to existing Miners' Safety Lamps.
Year: 1894

page_text: Date of Application, 21st Mar., 1894
Complete Specification Left, 9th June, 1894-Accepted, 14th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in Miners' Safety Lamps, which Improvements are
partly applicable to existing Miners' Safety Lamps.
We, WILLIAM BARNS, Junior and CLAUDIUS OWEN HILLSDON, both of
Christopher Works, Chalton Street, Euston Road, London, Inventors, do hereby
declare the nature of this invention to be as follows :—
Our first improvement relates to improved means for conveying air to the
combustion chamber of the lamp in order to prevent the air current impinging
directly upon the flame thereby producing a steadier and brighter light, and
reducing to a minimum the risk of explosion and extinguishment by adapting the
lamp to be used with safety in air currents of high velocity. To effect this we
make a series of perforations in the flange whereon the hood of the lamp rests,
which flange is carried on tubular supports. These perforations serve to admit air
into an annular or other conveniently shaped chamber formed in the flange of such
hood from which chamber the air is led down the tubular supports and thence
passes into the ring which supports the lamp glass that forms the combustion
chamber of the lamp. The products of combustion are carried off through the
lamp chimney which forms a separate uptake and thence escape through the gauze
cap of such chimney. By this means we form a separate intake and uptake for the
air, and so promote its freer circulation thus producing more perfect combustion and
better illumination.
Our second improvement relates to an automatic locking arrangement which is
applicable to existing miners' lamps as well as to those specially constructed as
above described and has for its object to effectually prevent the lamp being opened
by any unauthorised person. Such automatic locking arrangement consists of a
spring bolt furnished with a threaded end and fitted in the base of the lamp through
which base it slightly projects on the inner side. A cam piece is cast or otherwise
formed on the top of the reservoir of the lamp. in such a position that when the
reservoir is screwed to the base the projecting end of the bolt comes in contact
with such cam piece, and is depressed thereby, thus allowing the cam to pass.
When it has so passed the bolt resumes its normal position thus securely locking
the lamp. The base of the lamp is fitted externally with a socket piece, through
which, when it is desired to unlock the lamp a screw key is inserted which engaging
with the threaded end of the bolt compresses the spring thereof and withdraws the
bolt, thus allowing the cam to pass freely as the reservoir is unscrewed.
ELT & Co.,
33, Southampton Buildings, London, W.C., Agents for Applicants.
COMPLETE SPECIFICATION.
Improvements in Miners' Safety Lamps, which Improvements are
partly applicable to existing Miners' Safety Lamps.
We, WILLIAM BARNS, Junior, and CLAUDIUS OWEN HILLSDON, both of
Christopher Works, Chalton Street, Euston Road, London, Inventors, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to improvements in miners' safety lamps and has for its

page_text: object. Firstly. To reduce the risk of explosion and extinguishment to a minimum.
Secondly. To obtain more perfect combustion and better illumination and
Thirdly. To prevent the lamp being opened by any unauthorised person.
Our first improvement relates to improved means for conveying air into the lamp
so as to prevent the air current impinging directly upon the flame and also to
To effect this we
providing a separate intake and uptake for such air current.
make a series of intake apertures round the hood of the lamp. These intake
pertures are preferably arranged in a circular form and are placed on a level
somewhat below that of the top of the lamp chimney so as to prevent the intake
air current mingling with and partially intercepting and counteracting the uptake
air current in such chimney as now frequently occurs. The bottom of the hood is
fitted with a perforated flange furnished round its circumference with recessed lugs
that form caps for tubular supports presently mentioned and also on its underside
with two projecting rims the space between which latter forms an air chamber
wherein the intake air current circulates after passing through the perforated
flange and is thence conducted down tubular supports that carry the top of the
lamp frame into a second air chamber situate between the ring which supports the
glass that forms the combustion chamber of the lamp and the top of the reservoir..
This second air chamber is formed by means of a threaded collar furnished with.
hollow threaded bosses into which the lower ends of the tubular supports take and
are screwed thus fixing the collar in position. When so fixed the top of the:
reservoir which is likewise screw threaded and has a projecting flange formed
thereon around its circumference is screwed into such collar and tightened up until
such projecting flange butts against the bottom of the collar thus forming a stop
and so causing sufficient space to be left to form such second air chamber between
the top of the reservoir and the ring which carries the lamp glass. Suitable
apertures are cut in the threaded collar behind each of the before mentioned
hollow bosses to allow the air to pass into and circulate through such second
chamber from whence it passes up into the combustion chamber of the lamp to
feed the flame and after being consumed therein the products of combustion are
carried off through the lamp chimney which forms a separate uptake therefor and
thence escape through the gauze cap of such chimney and pass out at the top of
the lamp in the ordinary manner. By thus indirectly conveying the air into the
lamp we prevent such air current impinging directly upon the flame and so reduce
the risk of explosion and extinguishment to a minimum thus enabling the lamp to
be used with safety in air currents of high velocity while by providing a separate
intake and uptake for the air we promote its freer circulation and obtain more
perfect combustion and better illumination.
Our second improvement relates to an automatic locking arrangement which is
applicable to existing miners' safety lamps as well as to those specially constructed
as above described and has for its object to effectually prevent the lamp being
opened by any unauthorised person. Such automatic locking arrangement consists
of a bolt furnished with a threaded end and having a coiled spring mounted
thereon. This bolt is fitted in the threaded collar already described through which
it slightly projects on the inner side. A cam catch is cast or otherwise formed on
the top of the reservoir of the lamp in such a position that when the reservoir is
screwed into the threaded collar the projecting end of the bolt comes in contact
with such cam catch thus compressing the coiled spring and depressing the bolt and
so allowing the cam to pass. When it has so passed the coiled spring again
expands thus causing the bolt to resume its normal position and so securely locking
the lamp as shewn in Figure 2 of the accompanying drawings. The threaded
collar has a hollow boss cast or otherwise formed thereon. This boss is fitted with
a socket piece into which when it is desired to unlock the lamp a screw key is
inserted which engaging with the threaded end of the bolt compresses the spring
and so withdraws the bolt thus allowing the cam catch to pass freely as the reservoir
is unscrewed. The coiled spring is kept in position by means of a collar on the
neck of the bolt and a shoulder on the end of the socket piece between which it is

page_text: placed and which form bearings to keep it up to its work. It will thus be seen that
it is impossible to open the lamp when it is once locked without the master key.
DRAWINGS.
Figure 1 of the accompanying drawings shews a vertical section of a miner's
safety lamp constructed according to our invention.
Figure 2 is a plan view shewing the ring which carries the lamp glass and the
reservoir screwed into the threaded collar and the automatic locking mechanism
which latter is shewn in section and
Figure 3 is a plan view of the perforated flange on the bottom of the hood.
Similar letters of reference indicate corresponding parts in all the figures.
a, are the intake apertures. b, the perforated flange with recessed lugs 61, which
c, the
form caps for the tops of the tubular supports and projecting rims 63, 63.
air chamber between such rims. d, the tubular supports. e, second air chamber.
fring which carries the glass f₁ that forms the combustion chamber of the lamp.
9, the reservoir with projecting flange g¹. h, threaded collar with hollow threaded
bosses h', apertures h, to allow the air to pass into the second air chamber e and
hollow boss h³, fitted with socket piece h, whereon is a shoulder ho, against which
the outer end of the coiled spring takes its bearing. i, bolt with threaded end i¹,
coiled spring, and collar ³, which forms a bearing for the inner end of such
coiled spring. j, cam catch which engages with bolt head. k, screw key which in
Figure 2 is shewn engaging with the threaded end of bolt in readiness to draw
back the bolt head so as to allow the cam catch to pass.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
1. In a miner's safety lamp the improved air intake consisting of intake apertures
perforated flange, with air chamber, tubular supports, and threaded collar with air
chamber in combination with a separate uptake through the chimney, gauze cap
and top of hood all constructed arranged combined and fitted substantially as
herein before described and shewn.
2. In a miner's safety lamp the improved automatic locking mechanism consisting
of a threaded spring bolt operated by a screw-key and working in and through a
collar and socket fitted to the base of the lamp in combination with a cam catch all
substantially as hereinbefore described and shewn.
Luna LX07
Dated
en bus
ELT & Co.,
33, Southampton Buildings, Chancery Lane, London,
Agents for Applicants.