Improvements in Lead Sheath Cables.
Year: 1894

page_text: Date of Application, 21st Apr., 1894
Complete Specification Left, 7th Jan., 1895-Accepted, 9th Feb., 1895
I, JAMES BASNETT ATHERTON of Manhattan, Rainhill in the County of
Lancaster, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
Among the numerous devices for covering telegraph cables which have been
produced from time to time to more effectually insulate them is a lead coating
formed by squirting lead round the cable in a press. Now this lead coating is
liable to be permeated by fine air bubbles or as they are technically termed pin
holes and in order to guard against this the lead covered cable is tested by
immersion in water under a sufficient head. As however the cable itself is of an
oily character it affords considerabie resistance to the water and consequently a
cable that has been tested and is apparently clear of faults proves often very
defective after remaining for some considerable period in the water or in wet
ground.
Now this invention is designed to prevent the chance of these pin holes and it
consists in forming an alloy of lead round the lead itself. For this purpose I pass
the lead covered cable through a bath molten or electrolytic preferably the former of
metal capable of easily forming an alloy with tiu, and having a lower melting point
than the lead itself, such a metal is tin. By this means the lead is tinned over and
any minute pores that there may be in the lead are filled up with the tin making
the tin, or alloy of lead and tin quite impermeable to water.
The tin also assists
in resisting corrosion and further gives the lead covered cable a silvery appearance.
Dated the 20th day of April 1894.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in Lead Sheath Cables.
I, JAMES BASNETT ATHERTON of Manhattan, Rainhill in the County of
Lancaster, 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 :-
Among the numerous devices for covering electric cables which have been
produced from time to time to more effectually protect them, is a lead coating
formed by squirting lead round the cable in a press. Now this lead coating is
liable to be permeated by fine air bubbles or as they are technically termed pin
holes, and in order to guard against this, the lead covered cable is tested by
immersion in water under a sufficient head. As however the cable itself is of an
oily character it affords considerable resistance to the water and consequently a
cable that has been tested and is apparently clear of faults proves often very
defective after remaining for some considerable period in the water or in wet
ground.

page_text: Now this invention is designed to prevent the chance of these pin holes and
consists practically of forming a coating of an alloy of lead or another metal on the
lead coating after the same has been manufactured. For this purpose I prefer a
less oxidisable metal and one more fusible than lead. Such a metal is tin. The
best plan of forming the coating which I have as yet devised is to pass the cable
with its lead armour through a bath of molten tin in which solid tin is floating, and
brush off the superfluous liquid tin, as it emerges from the tank, by passing it up
through revolving brushes or better through a die. By this means the lead is
tinned over, and any minute pores that there may be in the lead are filled up with
the tin, making the tin, or alloy of lead and tin quite impermeable to water. The
tin also assists in resisting corrosion and further gives the lead covered cable a
silvery appearance.
It is obvious however that nearly the same result may be obtained by passing
it through an electrolytic bath where tin or nickel or other like metal can be
deposited upon it. This plan is however not as good as the tinning process above
described, first, because the coating is not chemically combined with the surface of
the lead, as it is in tinning, and second, it is more liable to flaws and imperfections,
and third, if the pin hole were large enough it might allow the electrolytic fluid to
enter the cable, while if not large enough for the fluid to enter the pin hole is at
best covered up by a very thin coating instead of being partially filled up with an
alloy as it is in tinning. I merely mention this inferior plan as a colourable
imitation of my invention to prevent others afterwards laying claim to it as a new
and independent invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that
what I claim is :-
1. The improvement in lead sheath cables which consists in a coating over the
lead of another closely adhering metal or alloy, or combination of these substantially
as described.
2. The improvement in lead sheath cables which consists in a coating over the
lead of tin formed by passing the lead sheathed cable through a bath of molten tin.
Dated this 2nd day of January 1895
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.