Improvements in Portable Electric Lamps for Use in Mines and other Places.
Year: 1895

page_text: Date of Application, 20th Dec., 1895
Complete Specification Left, 19th Sept., 1896-Accepted, 19th Dec., 1896
Improvements in Portable Electric Lamps for Use in Mines and
other Places.
SYDNEY FERRIS WALKER, Electrical Engineer Cardiff Electrical Works
Severn Road, Cardiff, S. Wales, do hereby declare the nature of this invention to
be as follows :-
My invention relates to that class of electrical apparatus in which a supply of
electrical energy in the form of a galvanic battery, is carried in any suitable
receptacle, with an incandescent electric lamp attached thereto.
In my invention, I use only one galvanic cell, which I prefer to be of the
primary type, tho' I sometimes use one of the secondary type.
In either case I use an incandescent lamp made to work with the normal voltage
of the cell, the requisite amount of energy being made up by proportionately
increasing the current strenth above that required when more than one cell is
employed.
When I use a primary battery, 1 make one of the elements the containing
vessel, preferably the negative element, and I attach the other element to the cover
of the vessel, forming a portion of the cover of insulating material for that
purpose.
I also attach the incandescent electric lamp to the cover, by preference, by a
suitable connection between the terminals of the lamp, and the two portions' of
the cover; but I sometimes attach the incandescent lamp to other portions of the
apparatus.
I protect the incandescent lamp, either by making it's own bulb of very stout
glass, or by an outer protecting glass.
I use any suitable form of galvanic battery, and any suitable form of incan-
descent electric lamp, the combination of which will furnish the amount of light
required in each particular case for the time required.
I provide a handle in any convenient position for carrying the lamp by, when
required.
DL: 1011
hon 1005
COMPLETE SPECIFICATION.
Improvements in Portable Electric Lamps for Use in Mines and
other Places.
SYDNEY FERRIS WALKER, Electrical Engineer Cardiff Electrical Works
Severn Road, Cardiff Glamorgan, 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 :-
My invention relates to that class of electrical apparatus, in which the supply of

page_text: electrical energy, in the form of a galvanic battery, is carried in any suitable
receptacle, with an incandescent lamp attached thereto.
One great difficulty in connection with the use of portable electric lamps in
which the electrical energy is provided in the form of a galvanic battery that can
easily be carried about from place to place, has been the fact that hitherto the
batteries used have consisted of several cells, the connections between which and
the connections between them and the lamp, have been troublesome to make, and
difficult to maintain in proper working order.
Other difficulties have been the maintenance of the electrodes themselves in
proper working order, and the preservation of the vessel containing the battery
from damage in use, and from the action of the acids used in the battery.
In my invention, I dispense with nearly all connections, by using only one
galvanic cell, which may be of the primary or secondary type, and I use an
incandescent lamp made to give it's normal light, when electrical energy is
supplied to its terminals, at the pressure furnished by the single cell itself.
In order, also, to protect the outer case from damage in use, or from the acids
used in the battery, I arrange that the outer containing vessel shall be of metal,
sufficiently strong to stand the usage it will be subject to, and I either arrange
that the outer containing vessel shall itself form one of the electrodes, or I protect
it on the inside by a coating of enamel, sulphur or other insulating substance
that will resist the action of the acids used in the battery, or I provide an inner
vessel of specially thin hard glass, or porcelain, fitting as closely as possible to
the outer case, the intervening space being filled with sulphur, or such other
substance as will resist the action of the acids used in the battery.
For some purposes, also, I protect the outer containing vessel on the outside
with enamel, or any substance that will resist the action of the acids used in the
battery.
I prefer to make the outer containing vessel in the form of a cylinder, closed at
one end, and I make it preferably of aluminium, but I also use thin steel, and
other metals for the purpose.
In making the outer case, I have the metal sheet of which it is to be composed,
specially prepared, and I then stamp it into the form required.
I do this, that there may be no joints or other special points of attack for the
acids used in the battery.
I sometimes also make the outer containing vessel square, bexagon, or other
form, in section, but when I do so I take special precautions in the preparation &
stamping of the metal sheet, to ensure there being as little difference as possible in
thickness, and in compression in the different parts of the vessel.
I provide a flange on the outer circumference of the cylinder at the open end,
preferably of the same metal as the cylinder itself, securely fastened to the cylinder
itself, and of sufficient thickness that a coarse pitched screw thread may be cut on
it, and I also sometimes provide a similar flange, with an annular ring attached,
on the inside of the open end of the cylinder.
I provide a cover for the cylinder, consisting partly of metal, and partly of
insulating material. That is to say I take for this purpose an annular ring of
metal, and attach to it a flanged ring of the same metal, the two being of such a
size, that when a screw thread, of the same pitch as that on the outer flange of the
containing cylinder, is cut on the inner periphery of the cover flange, the two will
engage together as male & female screws.
To the annular metal disc, which I make when practicable, of the same metal as
the containing vessel; I attach a disc of insulating material, and to this disc
I attach a disc. of metal, where only one electrode is carried by the cover, and in
addition a second annular ring of metal, where both electrodes are carried by
the cover.
I arrange so that when the cover is screwed fully down on the open end of the
cylinder, the vessel is closed so as to be liquid proof.
I sometimes use other forms of fastening between the cover, and the containing

page_text: vessel, such as a close fitting flange with a bayonet joint, or the same with one or
more screws to hold it in position.
In some cases I provide a second inuer flanged ring attached to the cover, to
which I attach an annular ring of rubber, or other suitable material, the whole
being so arranged, that when the cover is screwed down, the rubber ring attached
to this inner flanged ring of the cover presses on the inner annular ring of the
containing vessel.
To the under side of the cover I attach one, or both, of the electrodes, to be
used in the battery, making suitable connections of large cross section, but as small
surface as possible, between the metal disc and annular ring forming part of the
cover as described above, and the electrodes respectively.
I provide suitable arrangements, either by screws, or in any suitable manner, for
the removal of the electrodes from the cover.
I prefer to use amalgamated zinc for the positive element of the battery, where
I use a primary battery, but I also sometimes use iron & other metals.
I also prefer to connect the positive element to the disc in the centre of the
cover by means of a male threaded screw of coarse pitch projecting downwards,
the top of the positive element, which I prefer to make in the form of a cylindrical
rod, being fitted with a female screw of similar pitch, to engage with it.
I prefer to provide also, by arranging the acids used in the battery, that the
positive element employed shall be only of sufficient size & weight to last for one,
or at most two charges, but where required I make them of sufficient size to last
several charges.
I find, however, that the constancy of the current obtained from the battery is
maintained best by frequent renewals of the positive element.
Where the containing vessel is also the negative element, no further attachment
is made to the under side of the cover.
Where the negative element is also attached to the cover, when I use a primary
battery, I prefer to use carbon of the very purest & hardest form obtainable for
this negative element and I further prepare the carbon, by filling it's pores with
paraffin, sulphur, boron or any other material that will resist the action of the
acids used in the battery.
I support the carbon by a metal collar or by brackets, projecting downwards,
and attached to the cover.
1 prefer to have the carbon in the form of a hollow cylinder, the positive element
being inside it, but I sometimes use plates, or other forms for both the positive &
negative elements.
I protect the connecting pieces on the under side of the cover, and all the
exposed parts, by coating them with sulphur, or other acid resisting material, using
any suitable material, or combination of materials.
Where I use a secondary battery, I attach the positive & negative plates to the
cover of the case in a similar manner to that already described.
When I use a primary battery I use any suitable solution, but I find that in
order to be able to use only a small surface of positive element and to maintain a
constant current for the time the lamp is required to be in use, I require a very
powerful combination of chemical salts, combined with chemical salt that will retard
the action upon the positive element.
On the upper surface of the cover of the outer containing vessel as already
described, I place the lamp and any attachments belonging to it.
I make the lamp of the ordinary incandescent type, its filament being of the
proper size & length to furnish the necessary light, with the pressure & current
delivered by the battery, the battery being made of a size and weight proportional
to the light required, and the number of hours it is to burn. I arrange that the
terminals of the lamp shall be connected either to plates or collars, and I
arrange that these shall either slip into a bayonet socket, screw into a female
screw of coarse pitch, the lamp terminals being fitted with a male screw of similar

page_text: pitch, or be held in place & connected to the disc & ring on the cover, by a screwed
locking collar, or I arrange the connections, both electrical and mechanical by any
suitable means that will hold the lamp firmly in its place, and provide good electrical
connections.
I either make the bulb of the lamp itself, where the ordinary incandescent lamp
is used, of very thick strong glass, so that it will stand the usage of mines and
similar places, or I provide an outer strong protecting glass, held in its place by a
screwed locking ring, or other suitable means.
I also sometimes provide a reflector for the lamp, for the double purpose of
increasing the light given in any direction by utilising the back rays, and also for
the purpose of cutting off the rays of light where they are not wanted, or would
do harm.
I sometimes make this reflector part of the lamp globe itself, by pasting or
depositing a thin layer of metal over one portion of its surface. I also make the
reflector in the form of a thin metal, preferably an aluminium, concave shield
moveable round the lamp, and attached to it in any convenient way.
In the accompanying drawings
Fig. 1 represents a front elevation of one form of the complete apparatus
including battery, and lamp & reflector and handle.
Fig. 2 represents a sectional elevation of the battery, with it's cover, case & two
electrodes where two are employed.
Fig. 3 represents a plan of the cover when two electrodes are employed.
Fig. 4 represents a sectional elevation of the battery & cover where only one
electrode is employed.
Fig. 5 a plan of the cover with only one electrode.
Fig. 6 represents a sectional elevation of the cover & the lamp, where only one
electrode is employed, showing the connections between the lamp & battery by
means of a bayonet socket joint.
Fig. 7 shows the cover with the lamp & connections when a screwed locking
ring is used.
Fig. 8 shows the cover & lamp, where the connection between the two is
made by means of a coarse pitched screw & a central stud. The arrangement
of the connections between the cover & the lamp is the same when two electrodes
are employed, as when only one is used, except that the second connection is made
to the metal ring holding the carbon cylinder in place of to the outer ring.
In all the drawings A is the outer metal case, preferably made of aluminium,
B is the metal cover engaging by means of the screw thread shown, with the
screwed flange shown at the top of the vessel A. C is the disc of insulating
material, separating B from I the ring to which the carbon cylinder is attached,
when two electrodes are employed, and from D the central disc to which the zinc
element is attached, when only one metal is employed. F is the ring or disc of
insulating material between the metal ring supporting the carbon cylinder and the
metal disc supporting the zinc. E is the end of the zinc rod screwed into the metal
disc D. His the glass or porcelain cylinder inside the outer containing vessel,
L is the sulphur or other material filling the space between the metal cylinder A
and the glass or other cylinder H.
a is the incandescent lamp globe, b the lamp filament, c c the connecting plates
at the bottom of the lamp in Figs. 6 & 7, c & d are the bottom contact plate &
screw connection in Fig. 8. ee is the hollow cylinder forming the socket into
which the lamp is fixed, insulated where necessary from the metal rings forming
the cover, ff are the plungers, with their outer cylinders forming the connection
between the bottom plates c c & the metal discs on the cover in Fig. 6. kk is the
locking collar with its female screw engaging in a male screw on a flange held on
top of the cover but insulated from it in Fig. 7. R is the reflector enclosing the
lamp, S a glass or lens in front of the reflector, ✗ the handle to carry the
lamp by.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is,
1. A portable electric lamp in which a single primary galvanic cell is
employed.
2. A portable electric lamp in which a single secondary cell is employed.
3. A portable electric lamp constructed and arranged substantially as
described.
4. The use of the outer containing vessel, as an element of the battery itself, in
a portable electric lamp.
5. The use of an electric glow lamp of any form, in a portable electric lamp,.
arranged to furnish its normal light when current is delivered to it's terminals at.
the pressure created by a single galvanic cell.
L Cat 1906