Improvements in Primary Batteries.
Year: 1893

page_text: Date of Application, 10th Nov., 1893
Complete Specification Left, 10th Sept., 1894-Accepted, 10th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Primary Batteries.
I, WILLIAM HEaton Longsdorf, of Grosvenor Club 135 New Bond Street,
in the County of London, Merchant, do hereby declare the nature of this invention
which has been communicated to me by Gardner Hewett, of 29 Broadway in the City
of New York, United States of America, Electrical Engineer, to be as follows:-
My invention relates to galvanic batteries and has special reference to that type
known as the "Gravity." The objects sought to be attained are to produce a battery
giving a large current for a long period of time; cheap and simple to construct and
in which the elements are so arranged and constructed as to maintain a well defined
"gravity line."
These objects I accomplish by the use of a new combination of solution and
depolarizing agent and a construction and arrangement of parts hereinafter described
in which the carbon element is made in the form of a hollow cylinder or cup into
which the depolarizer is placed in a solid state so that it may gradually dissolve.
I construct this battery with an outer vessel which may be conveniently of
cylindrical form, fitted with a cover of nonconducting material.
Both electrodes may conveniently be attached to and supported by the cover.,
The positive electrode is carbon while the negative, as usual, is of zinc. The
carbon is in form of a hollow cylinder closed at bottom or cup shaped, in either case
pierced at bottom or near it with one or more perforations, and may be secured to
the under side of the cover concentrically therewith and is fitted with a binding nut
for attaching the line wire. The carbon, hereinafter referred to as the carbon cup,
may conveniently be a little more than three quarters of the height of the outer
vessel so that when in position there will be considerable space between the bottoms
of the two vessels.
The carbon cup is made of dense carbon and may or may not, according to
circumstances, be treated from its upper end down to the gravity line with paraffine
or other material to make it impervious to liquids. Below the gravity line, or
otherwise where not paraffined, it is more or less porous and the bottom is as above
stated provided with one or more perforations to admit of free intercommunication
between the outer and inner vessels.
The zinc may be of any couvenient form but preferably in the form of a cylinder
surrounding and concentric with the carbon element and is attached to the cover
and has a binding screw to which the negative wire is attached.
In the outer vessel I place either a solution of common salt (chloride of sodium) and
sulphuric acid, or I may use bisulphate of soda, the quantity being such as to nearly
fill the vessel when the electrodes are inserted. In the carbon cup I place
powdered chromic acid or crystals of bichromate of soda, or bichromate of potash.
The electrodes then being attached to the cover are inserted in the outer vessel and
the cell immediately becomes active. Some of the solution from the outer vessel
passes through the perforations into the carbon cup and attacks and dissolves the
crystals there, forming a dense liquid which fills the lower part of both vessels up
to the gravity line above which the lighter liquids remain.
It will be observed that the walls of the carbon cup prevent agitation of the
liquids and thus tend to maintain a definite gravity line, and partly in consequence
of this stability the battery will remain constant in strength for a very long
period.
I find that the use of the said chemicals in the combination above named is of
particular value, as these materials, coupled with the arrangement of the parts as

page_text: described give a very strong, lasting and uniform current, and it will be seen that I
obtain this full use of the carbon surfaces by making the carbon cup the receptacle
for the crystals.
In some cases I do not paraffine the carbon cup at all but leave its natural
porosity to act throughout and by this means I can obtain a more powerful current
but the action is not so lasting.
Although the use of the materials specified is specially advantageous in the
particular form of cell described, the same materials may be used in other forms or
arrangements of gravity cell, and form a combination the action of which is
superior to any heretofore known combination for gravity cells.
Dated the 8th day of November 1893.
NEWNHAM BROWNE,
Agent for the Applicant.
Improvements in Primary Batteries.
1, WILLIAM HEATON LONGSDORF, of The Grosvenor Club, 135, New Bond
Street, in the County of Middlesex, Merchant, do hereby declare the nature of
this invention (a communication to me from Gardner Hewett, now deceased, but
late of 29, Broadway, in the City of New York, United States of America,
Electrical Engineer,) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
This invention relates to primary, galvanic or voltaic batteries, and has special
reference to what are known as 66
Gravity" batteries; the objects of the present
invention being to produce a cell or battery capable of giving a large current for a
long period; to lessen the cost of manufacture; to simplify the construction and to
so make and arrange the elements as to maintain a well defined "gravity line."
These objects are accomplished by the use of a new combination of solution and
depolarizing agent and a construction of cell having parts arranged as hereinafter
described; the carbon element being in the form of a cup or hollow cylinder in
which the depolarizer is placed in a solid state so that it may gradually dissolve.
The accompanying drawing shows in vertical section a cell constructed in
accordance with the present invention.
A is the outer vessel, which may be cylindrical and is fitted with a cover a of
non-conducting material. Both electrodes C and Z may be attached to and
supported by the cover a. The positive electrode C is made of carbon, while the
negative electrode Z is, as usual, made of zinc. The carbon electrode C is in the
form of a cup or hollow cylinder closed at the bottom, and is secured to the cover a
by a pin c and nut and pin c' and thumb-nut. In the bottom of the cup there are
perforations. The thumb-nut on the pin c¹ serves as a binding nut for the positive
wire. The electrode C, hereinafter referred to as the carbon cup, may be a little
more than three quarters of the height of the outer vessel A so as to leave a
considerable space in the cell between the bottoms of the two vessels A and C.
The carbon cup C is made of dense carbon and may be treated from its upper end
down to the gravity line with paraffin or other material to make that portion
impervious to liquids. The part of the cup which is thus rendered impervious is
hatched with thicker lines than the porous or lower part of the cup.
The zinc electrode Z may be of any convenient shape, but is preferably in the
form of a hollow cylinder surrounding and concentric with the carbon element C,
and is attached to the cover a by a pin z having a thumb-nut which serves as a
binding nut for the negative wire.
In the outer vessel A is placed a solution of common salt (chloride of sodium) and
sulphuric acid. Or bisulphate of soda or of potash may be used. The quantity of
solution is such as to nearly fill the vessel A when the electrodes C and Z are

page_text: inserted. The carbon cup C contains powdered chromic acid, or crystals of
bichromate of soda or of potash. Directly the electrodes are placed in the outer
vessel the cell becomes active. Some of the solution in the outer vessel A passes
through the perforations into the carbon cup C and attacks the crystals there,
dissolving them and forming a dense depolarizing solution which fills the lower parts
of both vessels A and C up to the gravity line. The dense solution is represented.
by thick dashes and the light solution above the gravity line by thin dashes.
The walls of the carbon cup prevent agitation of the liquids and thus tend to
maintain a definite gravity line, and partly in consequence of the stability so ensured
the cell remains constant in strength for a long period.
The use in the manner described of the chemicals specified above is of particular
value, as these chemicals, in a cell of the kind illustrated, give a strong, lasting and
uniform current; the full utilization of the carbon surfaces being obtained by
making the carbon cup the receptacle for the crystals.
If the carbon cup instead of being treated with paraffin be left porous all over,
the current is rendered more powerful but the action does not last so long.
Although the use of the materials specified in a cell of the particular kind shown
in the drawing is exceptionally advantageous, the same materials may be employed
in other gravity cells; the action resulting being superior to that obtained by any
combination of chemicals hitherto known for gravity cells.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :-
1. In a battery cell containing in its upper portion an exciting solution and below
that a depolarizing solution of greater specific gravity than the exciting solution,
the combination of a positive and a negative element, the latter being cup-shaped
and extending into both solutions, the lower portion only of the cup containing the
depolarizing agent, substantially as herein described.
2. In a gravity battery, a carbon cup porous at its lower end only and containing
a soluble depolarizing agent acting in combination with an exciting solution outside
the cup.
3. In a gravity battery, a carbon porous cup containing crystals of bichromate
of potash or of soda (or powdered chromic acid) acting in combination with a
solution of bisulphate of soda or of potash (or of chloride of sodium and sulphuric
acid) outside the cup.
4. In a battery cell having in its upper portion an exciting solution and below
that a depolarizing solution of greater specific gravity than the exciting solution,
the employment of a carbon cup containing a depolarizing agent and extending
from the upper portion of the cell downward into both solutions; the upper part of
the cup being impervious to liquids and the lower part furnished with openings.
5. A battery cell constructed and operating substantially as described with
reference to the accompanying drawing.
Dated the 10th
1004