IMPROVEMENTS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Allan Clark at the Office of the
Commissioners of Patents on the 13th July 1883.
ALLAN CLARK, of Glasgow, in the County of Lanark,
VOLTAIC BATTERIES,"
"
"IMPROVEMENTS IN
This Invention relates to improvements in single and double fluid batteries.
In forming single fluid batteries according to this Invention, a plate of zinc
forming the one electrode is fitted between two plates of platinum or carbon which
form the other electrode-To obtain increased surface the platinum or carbon
plates are corrugated, and these plates are soldered to a metal frame or binder, or
when carbon plates or blocks are used, their upper ends are copper plated and
soldered to the frame. The zinc plate has a saw cut made in it by which it is
attached to a separate metal frame or binder. The copper frame or binder carrying
the zinc electrode is conveniently fitted inside the frame or binder carrying the
platinum or carbon plates, the frames being insulated from each other by india
rubber or similar material, and the electrodes are immersed in an exciting fluid
contained in a pot or jar of suitable shape. The exciting fluid may be that
ordinarily used in bichromate of potash batteries to which I add a small proportion
of salt, or I use salt water as the dissolving liquid. The exciting fluid which I
prefer to use is composed of one part of salt, two parts bichromate of potash or
chromate of lime four parts sulphuric, hydrochloric or acetic acid, and sixteen parts
of water. In preparing this mixture which may be varied to suit the length of
time the battery is required to act, the acid is added last and very gradually, the
liquid being allowed to cool before being used. The object in adding the salt or
salt water is to keep the mixture solvent or prevent the formation of crystals, and
the advantage is also obtained that the length of time during which the battery is
active is greatly increased.
The zinc plate of the battery is amalgamated before use, and to maintain the
amalgamated surface on the plate a quantity of mercury, sufficient to outlast the
plate, is held either in a hole drilled or cast in the plate or in a cup attached to or
formed on it-This method of maintaining the amalgamated surface of the plate
may also be applied in amalgamating the zinc plates of single fluid batteries of
ordinary construction.

page_text: In forming a double fluid battery, the usual porous pot is employed and fitted
between the two electrodes. The zinc may be placed either within the porous pot
or in the outer pot, and the platinum or copper plates placed in the division
unoccupied by the zinc. The exciting fluid for the carbon or platinum is composed
of the ingredients above mentioned, and that for the zinc may be the same with
the bichromate of potash or chromate of lime omitted.
.
For convenience of lifting the plates out of the liquid when a number of cells
are joined up together, the copper frames or binders carrying the electrodes are
fixed to the wooden top or lid of a box which is used to hold the cells. The top
or lid is fitted with metal slides provided with spring catches to grip the ends of
the box and hold up the lid with the frames at any height that may be desired.
The projecting end of the top of the slide forms a handle to lift the lid.