IMPROVEMENTS IN ELECTRIC INSULATION
Year: 1864

page_text: LETTERS PATENT to Charles Hancock, of West Street, Smithfield, in the
City of London, Manufacturer, and Stephen William Silver, of Bishops-
gate Street, in the said City of London, Manufacturer, for the Invention
PROVISIONAL SPECIFICATION left by the said Charles Hancock and
Stephen William Silver at the Office of the Commissioners of Patents,
with their Petition, on the 14th December 1864.
We, CHARLES HANCOCK, of West Street, Smithfield, in the City of London,
Manufacturer, and STEPHEN WILLIAM SILVER, of Bishopsgate Street, in the
said City of London, Manufacturer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ELECTRIC INSULATION," to be as follows:-
We apply the milk of ballata and the milk of caoutchouc separately or
together to the surface of plain wires, or to wires coated or covered with
suitable materials by the taping or other process, and thereby render the
whole a well protected mass, affording a better insulation than has heretofore
been attained.
5
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Hancock and Stephen William Silver in the Great
Seal Patent Office on the 14th June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
HANCOCK, of West Street, Smithfield, in the City of London, Manufacturer,

page_text: and STEPHEN WILLIAM SILVER, of Bishopsgate Street, in the said City of
London, Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-four, in the twenty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto us, the said Charles Hancock and Stephen William Silver, Her special
licence that we, the said Charles Hancock and Stephen William Silver, our
executors, administrators, and assigns, or such others as we, the said Charles
Hancock and Stephen William Silver, our executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN ELECTRIC INSULATION," upon the condition (amongst others)
that we, the said Charles Hancock and Stephen William Silver, our executors
or administrators, by an instrument in writing under our hands and seals, or
under the hand and seal of either of us, particularly describe and ascer-
tain the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of
the said Letters Patent.
.
NOW KNOW YE, that we, the said Charles Hancock and Stephen William
Silver, do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained in
and by the following statement, that is to say :-
We declare the nature of the said improvements in electric insulation to
consist in applying the milk of ballata or the milk of caoutchouc, or a mixture
of the two to telegraph wires or other surfaces requiring electric insulation.
For this purpose we cause the wire to pass through a vessel containing the
milk, and allow one coat to become nearly or quite dry before we add a second,
and so on until the required thickness of coat is obtained. The milk may be
applied by means of a brush in cases in which the article cannot be conveniently
passed through or immersed in the milk. Bofore adding a second coat the
first coat is washed over with glycerine and water, or with fine pummice
powder and water to secure the even delivery of the second coat. Successive
coats may be applied in the same manner according to the requirements of
each case. The wire may also be insulated with ballata and caoutchouc in
the sheet state (as described in the Specification of Letters Patent granted to

page_text: us, dated Fifteenth December One thousand eight hundred and sixty-four,
No. 3110, by means of a taping machine according to a process which is well
understood in trade, one tape being laid over another until the required
thickness is obtained. A coating of the milk of ballata, or of the milk of
ballata and caoutchouc mixed is applied to the taping in order to further
insulate, and also to secure the lap of one joint upon the lapping of the other,
and this extra coating should be applied on each succeeding tape. The wire
may be covered with cotton, silk, wool, or other suitable material, and after-
wards coated or saturated with the milk of ballata and caoutchouc as above.
The insulation may be further protected by passing the covered wire through
the chloride of sulphur process which is well understood by workmen ex-
perienced in the vulcanizing trade.
The compounded milk of ballata and caoutchouc when in the state of
sheets or blocks may be masticated in a masticating machine, and applied to
coat and insulate telegraph wires by means of the ordinary covering machine.
The milk of caoutchouc, or the milk of caoutchouc and ballata combined
may be applied to telegraph wires which have had a previous covering of
india-rubber or india-rubber tape, or of india-rubber compound.
Having now described the nature of our said Invention, and in what
manner the same is to be performed, we hereby declare that we claim as of
our Invention, the improvement in electric insulation by applying the milk
or compound of ballata and caoutchouc either alone or in combination to the
surfaces to be insulated as above described.
In witness whereof, I, the said Charles Hancock, have hereunto set my
hand and seal, this Fourteenth day of June, in the year of our Lord
One thousand eight hundred and sixty-five.
CHARLES HANCOCK. (LS.)