Improvements in Galvanic Batteries for Producing Constant Currents.
Year: 1891

page_text: Date of Application, 1st Jan., 1891-Accepted, 21st Nov., 1891
COMPLETE
SPECIFICATION.
Improvements in Galvanic Batteries for Producing Constant
Currents.
I, WALTER WENSKY of 225 Friedrich Strasse, Berlin, S.W., Kingdom of
Prussia, German Empire, Manufacturer, 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:-
--
Of all the galvanic batteries yielding a constant current used hitherto the Marie-
Davy chloride of silver battery is the best; however, owing to its costliness it has
not met with general application.
The element hereinafter described, while affording the same convenience as to
constancy, is composed of considerably cheaper materials; moreover a larger
quantity of ampere-hours is obtained from my new cell. The electromotive force
is a little below that of the Daniel cell, but the current produced is of considerably
greater strength. The form of my element is that of the voltaic pile, and with but
two plates the efficiency of a Daniel cell is attained. As the element remains
equally constant during 50 to 60 hours without necessitating a renewal of the
materials and needing only about 60 grammes of depolarising salt, it is especially
qualified for the production of electric light. As a depolarising agent I employ
subchloride of copper, and have found the action of the same to be very energetic.
The electrodes of the element are copper and zinc plates.
The better to make my invention clear, I will proceed to describe a battery made
and worked according to my improvements by the aid of the accompanying
drawings, in which similar letters denote similar parts throughout the several views,
and of which :-
Fig. 1 is a cross-section through a battery of five cells placed one above the
other.
Fig. 2 an upper view of Fig. 1, partly in section.
The bottom-plate c of the lowest element consists of copper or of another electro-
positive material. Hereupon is placed a plate of felt », thereover an osmose-cloth o¹,
upon that a filling of powder of zinc p, covered with a second osmose-cloth o², and
on the top a plate of zinc u, to which is fastened the plate of copper c of the second
element, whereupon the other parts follow in the same order as in the first element.
Every cell is surrounded by rubber rings a outreaching the edge of the same and
keeping the different parts together.
1
Before the elements are put together, the free space between the lowest copper-
plate c and the lowest rubber ring a is filled with subchloride of copper; then I
pour in the exciting liquid, a 40 per cent. solution of chloride of zinc, to which I add
per cent. of perchloride of mercury, in order to keep the zinc well amalgamated.
The osmose-cloth is also impregnated with the above solution. The diameter of the
plate of felt should be smaller than the inner one of the rubber ring a.
The
hollow spaces are filled with subchloride of copper.
""
The elements being placed one above the other, two covering-plates d d are used
to join the same up and to hold them tightly together by means of the screws s.
The rubber-rings a make this battery air-tight and water-tight.
This is necessary
in order to prevent the access of the humidity of the air to the battery, because the
chloride of zinc formed in the latter is very hygroscopic and would cause the liquid
of the cells to overflow.
I will now proceed to explain the chemical and electrical action which takes
place in the battery.
The electric current decomposes the solution and hydrogen is formed at the
negative pole; this hydrogen combines with the chlorine of the subchloride, thus

page_text: forming hydrochloric acid and copper, the first almost immediately combining with
zinc to chloride of zinc, while metallic copper is precipitated on the copper plate as
a porous substance in form of powder; this precipitation begins near the copper
plate and gradually extends upwards, until the subchloride of copper is completely
transformed into chloride of zinc. Nevertheless, as the first of these salts is not
quite insoluble in hydrochloric acid, a quantity of the same might be dissolved,
which, when coming into contact with the zinc-plate u, would be decomposed and
leave a deposit of copper on the latter. This is prevented by the interposition of the
osmose-cloth and especially by the layer of powder of zinc, which may also conta'
oxide of zinc and for which powder of iron may also be substituted. The copper
which otherwise would be deposited on the plate of zinc u is precipitated on this
layer.
The plate of felt r has been interposed in order to ensure the contact by filling out
cavities, which are formed in the cell by contraction of the exciting liquid, due to
the chemical action.
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. An element for producing constant electric currents, having subch de of
copper as a depolarising agent.
2. An element for producing constant electric currents, having subchloride of
copper as a depolarising agent and provided with rubber rings between the single
cells, for the purpose as described.
3. An element for producing constant electric currents, having subchloride of
copper as a depolarising agent, and provided with rubber rings between the single
cells, and with double diaphragms separated from each otherby a layer of powder of
zinc or iron, for the purpose as described.
Dated this day of September 1831.
11S
day of September loji.
WALTER WENSKY,
By Rayner & Cassell,
37, Chancery Lane, W.C., Agents for the Applicant.