IMPROVEMENTS IN PORTABLE VOLTAIC BATTERIES
Year: 1882

page_text: LETTERS PATENT to James Mackenzie of Osnaburgh Street Regents Park
in the County of Middlesex for an Invention of IMPROVEMENTS IN PORTABLE
VOLTAIC BATTERIES
PROVISIONAL SPECIFICATION left by the said James Mackenzie at the
Office of the Commissioners of Patents on the 21st September 1882.
JAMES MACKENZIE of Osnaburgh Street Regents Park in the County of
Middlesex "IMPROVEMENTS IN PORTABLE VOLTAIC BATTERIES
"
My invention relates to the construction and arrangement of a chloride of
silver battery cell so as to be powerful in its action, tight against leakage and
conveniently portable. For this purpose I fit a short cylindrical tube of copper
brass or other suitable metal with a cap of the same metal screwed on one end, and
with a cover of ebonite or other insulating material screwed on the other end the
joints being made tight by washers of leather or other packing material. I electro-
plate with silver the interior of the tube and its metal cap and on this silvered
surface I fix by fusion a layer of chloride of silver. In the ebonite cover and
passing through it I screw a zinc pin and to the head of the pin, which is inside, I
secure by a zinc rivet a tube of zinc or amalgamated zine which extends nearly to
the bottom of the cell leaving an annular space between it and the interior surface
of the chloride of silver. The cell being charged with suitable exciting liquid
such as solution of sodium sulphate or chloride, or zinc chloride, the ebonite cap is
screwed on tight and the conducting wires for the external circuit are connected
respectively to the exterior of the tube and to the zinc pin which passes through
the ebonite cover.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Mackenzie in the Great Seal Patent Office on the
19th March 1883.
JAMES MACKENZIE of Osnaburgh Street Regents Park in the County of
Middlesex "IMPROVEMENTS IN PORTABLE VOLTAIC BATTERIES"
My invention relates to the construction and arrangement of a chloride of
silver battery cell, so as to be powerful in its action, tight against leakage, and
conveniently portable. Fig. 1 of the accompanying drawings is a vertical section
of my improved cell. A is a cylindrical tube of copper, brass or other suitable
metal, which is fitted at one end with a cap B of the same metal, that can be
screwed on to the tube with a ring of caoutchouc or other packing material
interposed to make the joint tight. Both the tube A and the cap B are plated
internally with silver and on their silvered surface is fixed by fusion a layer D of
chloride of silver. At the other end of the tube A is screwed a cover E made of
ebonite or other suitable insulating material. Through the centre of the cover E
is screwed a zinc pin F, to the externally projecting end of which is screwed a
binding screw C to take one of the conducting wires. The internal head of the
zinc screw F has fixed upon it by zinc rivets a zinc tube G, made by simply
bending a strip of sheet zinc into tubular form so as to leave free passage for the
exciting liquid between the adjacent edges of the zinc. The zinc tube reaches
nearly to the bottom of the cell but does not touch it, and around the tube,
between it and the chloride of silver lining, there is a clear annular space. The
cell being charged with suitable exciting liquid, such as solution of sodium sulphate
or of sodium chloride or of zinc chloride, the ebonite cover E is screwed tightly in,
and then a conducting wire connected to the zinc pin F, and another wire con-
nected to the exterior of the tube A will form an external circuit for the electric
current generated in the cell.
The cell may be made as shewn in Fig. 2 with ebonite covers H at both ends
held firmly by screwed caps K with washers of gutta percha or other suitable
packing material interposed between the covers and the ends of the tube. L is a
cork ring inserted in the end of the zinc tube G, and. M is a thin disc, which, in
case of excessive pressure within the cell, will give way.
The cell constructed as above described having the internal surface of its tube
silvered and coated with chloride of silver, and having its internal zinc tube
secured to a zinc pin, presents at each electrode only a single metal, and therefore
there is no liability to any cross polarization. As the covers are screwed tightly
against packing material, the cell can be placed or carried in any attitude without
the leakage of any part of its liquid contents.
Having thus described the nature of my Invention and in what manner the
same is to be performed, I claim :-
The construction of a portable voltaic battery cell, consisting of a closed tube
internally silvered and coated with chloride of silver, in combination with an
internal zinc tube held by a zinc pin passing through the insulating cover of the
tube, substantially as herein described.
In Witness whereof, I the said James Mackenzie have hereunto set my hand
and seal this fifteenth day of March in the year of our Lord One
thousand eight hundred and eighty-three.
JAMES MACKENZIE (L.S.)