Improvements in Electric Miners' Safety Lamps.
Year: 1890

page_text: Date of Application, 17th Apr., 1890
Complete Specification Left, 15th Jan., 1891-Accepted, 28th Feb.,
1891
PROVISIONAL SPECIFICATION.
Improvements in Electric Miners' Safety Lamps.
I, CHARLES POLLAK, of 23, Boulevard de Strasbourg, Paris, in the Republic
of France, Electrical Engineer.
This invention relates to an electric miners' safety lamp. This apparatus com-
prises accumulators for supplying the current, fittings serving to conduct the current
to the lamp, and an incandescent lamp.
All
The accumulators are enclosed in a case of ebonite divided in the middle through-
out its length by an ebonite partition. Accordingly the case has two compartments,
in each of which is arranged an accumulator composed of a positive plate placed
in the middle and having two active sides and two negative plates which are
connected with each other at the bottom of the case by means of two pins and
which have each one active side turned towards the positive plate whilst the other
side is held either against the side or against the partition of the said case.
the plates are supported upon triangular combs made of ebonite between which
interstices are left for receiving the substances that may fall to the bottom. The
negative plate of one of the accumulators and the positive plate of the other carry
each a rod forming a spring, which is provided at its extremity with a contact-piece
of platinum whilst the other two plates of the accumulators are connected by means
of a pin made of antimonious lead which extends through the partition.
Each
The aforesaid case is closed by an ebonite lid of special construction. The
underside of this lid is provided with a rebate at the edges and in the middle and
receives two small plates for fixing the said lid upon the sides of the case.
plate carries a T-shaped contact-piece of platinum secured to a pin made of anti-
monious lead which extends through the cover. One of the pins provided is free
whilst upon the other is fixed the extremity of a copper strip whose other extremity
is secured to one of two small copper tubes sunk vertically into the lid of ebonite.
These tubes serve for receiving the two spring connections of the incandescent
lamp. The aforesaid lid has three horizontal channels, the object of which is to
establish the desired connection. The two outer channels extend in a direction
tangential to the pins fixed to the platinum contact-pieces; they establish a direct
connection between the positive and negative poles of the battery. This com-
munication is established during the charging of the lamp.
The channel in the middle extends in a direction tangential to an insulated
vertical tube designed to receive one of the connections of the incandescent
lamp.
In order to cause the current to pass through the lamp during the discharge a
U-shaped copper wire forming a spring is inserted into one of the outer channels and
into the channel in the middle. For establishing the above-mentioned connections
use can be made of suitable switches placed on the said lid, instead of the channels
hereinbefore described.
Upon the underside of the lid is arranged a disc or plate of indiarubber in order
to ensure a perfectly tight joint between the lid and case.
a
Two small holes are formed in the cover to enable the escape of the gas.
Around the lamp is placed a glass cylinder the lower edge of which is held in
circular groove formed in the above mentioned lid. This-cylinder is closed above
by a cap consisting of copper. The lamp rests on a support upon which are secured
When the lamp has been
vertical rods provided at their extremities with nuts.

page_text: placed upon the support it is covered with the aforesaid cap whereupon the nuts are
tightened.
Dated this 17th day of Anvil 1890
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electric Miners' Safety Lamps.
I, CHARLES POLLAK, of 23, Boulevard de Strasbourg, Paris, France, Electrician,
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:-
The object of this invention is a miner's electric lamp, composed of three parts;
viz.: accumulators as the source of current; a system of connections for conducting
the current to the lamp; and an incandescent lamp.
Figures 1 and 2 are respectively vertical sections on the lines M, N, Figures 3
and 4, and of P, Q, of Figure 3.
Figure 3 is a horizontal section on the line R, S, of Figures 1 and 2.
Figure 4 is a plan from above the cover of the box containing the electric
accumulators, and Figure 5 is a plan with the cover removed.
Figures 6 and 7 represent one of the triangular combs of ebonite on which the
accumulators rest.
Figure 8 represents the pin or skewer which sets the lamp in action, and Figure 9
shows the double rod for enabling the accumulators to be charged.
The accumulators are enclosed in an ebonite box A separated at the middle by
an ebonite partition B, dividing the box into two compartments C and D. In each
compartment there is an accumulator composed of a positive plate a placed in the
middle, acting on both its faces; and of two negative plates b, b, connected together
at the bottom of the box by means of two rods c, c, each acting by the surface
which is turned towards the positive plate, the other surface being turned towards
the side of the box.
The negative plate 6 of one of the accumulators, and the positive plate a of the
other each carries a rod d, e, acting as a spring and having a platinum contact f, f,
at its end. The two other plates of the two accumulators are connected by a pin g
of lead coated with antimony, and passing through the partition.
The box is closed by an ebonite cover plate E of special construction, and has on
its under part the platinum contacts which are intended to press upon the
contacts, on the rods d, e of the positive and negative plates of the accumulator.
The contacts h, h, are soldered to rods o, o, of lead passing through the cover and
fixed to curved spring blades, or strips i, ¹. These strips carry gudgeons j, j',
which penetrate into holes in the cover as far as the horizontal grooves or
channels m, m¹. These two longitudinal grooves or channels are for establishing
the required communications.
One of the rods o is connected by the tongue k to one of the tubes " which
receives one of the lamp connections.
In order to light the lamp, the pin or skewer y (Figure 8) is pushed into the
hole m and with its point it raises the gudgeon of the strip i, the gudgeon
continuing to rest upon the pin; the latter also comes in contact with the second
lamp supporting tube 1. The current from the accumulators then passes through
the lamp.
In order to charge the accumulators, the skewer y being removed, the rods z, z,
connected by an insulating block are introduced into the holes m, m', the rods touch
and raise the two gudgeons j, j, of the strips i, i, and by connecting one rod z to
the positive pole of an electric generator or source, and the other to the negative

page_text: pole, the accumulators become charged. As the channel m¹ is not so long as the
channel m the rod in the latter cannot reach the tube l, the accumulators alone
are therefore in circuit, and the lamp cannot be affected and deteriorated by this
current.
A special feature in this invention is the safety of the lamp, by reason of the
impossibility of unscrewing the nuts which hold the copper cap H and the glass
cylinder G, because it is only when these nuts are screwed home that the parts h, h,
and the rods d, e, are in contact.
If therefore the nuts v, v, be unscrewed or the glass G be broken, the contact
ceases and the current no longer passes through the lamp. This feature is one of
the great advantages of my lamp.
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, I declare that what I claim is :
;-
1. A portable electric lamp composed of an accumulator which is placed in one
or more vessels, a cover closing the vessel or vessels and supporting the switch, the
incandescent lamp and the chimney (glass cylinder) the latter surrounding the
incandescent lamp and covered with a plate and bolts and nuts holding together all
these parts in such a manner that the breaking of the glass cylinder surrounding the
incandescent lamp, or the unscrewing of the nuts causes the interruption of the
circuit of the current which feeds the incandescent lamp.
2. In a portable lamp, the employment of platinum contacts placed in the
accumulator receivers, as described.
3. The method of establishing the communication by means of the channels
formed in the cover.
4. The combination of the rods placed in the cover, thus protecting the contacts
from the fumes of the acids.
5. For the purpose of lighting the lamp, the introduction of a pin into the cover,
the point of which pin raises one of the contact strips, the said pin itself making
contact with the second lamp carrier tube.
6. For the purpose of charging the accumulators, the introduction of two pins
insulated into holes in the cover, which pins form contact with the two strips or poles
of the accumulator, in such manner that by connecting the pins to the poles of an
electric source the accumulator becomes charged without affecting the lamp.
The 15th day of January 1000
It Out Cay UL Juar
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said Charles Pollak.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said Charles Pollak.