An Improvement in the Manufacture of Tubes by Electrolysis.
Year: 1891

page_text: Date of Application, 23rd Mar., 1891
Complete Specification Left, 21st Jan., 1892-Accepted, 27th Feb., 1892
PROVISIONAL SPECIFICATION.
An Improvement in the Manufacture of Tubes by Electrolysis.
We, FRANCIS EDWARD ELMORE, and ALEXANDER STANLEY ELMORE, both of
Spring Grove, Hunslet, Leeds in the County of York, Electrometallurgists, do
hereby declare the nature of this invention to be as follows:-
:-
For the manufacture of tubes by electrolysis as described in former Speci-
fications No. 4499 and No. 8707 of 1885, No. 15831 of 1886, No. 16637 of 1887,
No. 11778 of 1888 and No. 2618 of 1889 a mandril, operating as a cathode is
caused to revolve in an electrolytic bath in which there is an anode of the metal to be
deposited, and the anode and cathode being connected to a source of electricity,
the metal as it is deposited on the mandril is rendered dense, compact and homo-
geneous in structure by a burnisher pressing against it and travelling to and fro
longitudinally while the mandril revolves. Sometimes the burnishing tool is in
the form of a roller made to revolve with a surface speed differing from that of the
mandril so as to rub as well as roll on the surface of the deposited metal, but it is
found that the best effect is produced by the use of a rod of agate or equivalent
hard mineral having its end of small area pressed against the surface of deposited
metal.
When the metal has been deposited to the desired thickness on the mandril it has
to be removed in the form of a tube.
Our present invention relates to the preparation of suitable mandrils and means
of facilitating the removal of electrolytically deposited tubes from the mandrils on
which they are deposited.
To form the mandril, we select a sound smooth tube, preferably one that has been
itself electrolytically deposited with continuous burnishing, and, having got the tube
as truly straight and circular as possible and mounted it centrally on an axis, we
expose it for a short time to the air by which a thin film of oxide is formed upon
its surface or we wash it with a sulphide solution or coat it with a thin solution of
wax in alcohol or otherwise treat it in any known manner to prevent adhesion of
the deposited metal to it. We then immerse it in the bath causing it to revolve
therein with a burnisher moving along it in the usual way, until a thin shell of
metal is deposited on it. We then substitute for the burnisher a narrow roller
which is pressed against the deposited metal and is, like the burnisher, caused to
travel along it, but not quite to one of the ends.
This has the effect of slightly stretching the deposited shell circumferentially
and loosening it from the mandril. During the subsequent depositing process,
which may be continued for the required time to produce a deposit of desired
thickness, the looseness on the mandril remains as at first, and when the deposit
is completed it is only necessary to part off and remove the narrow band of metal
at the one end which had not been loosened by the roller, and then the tube can
be readily slid off the mandril. For mandrils of considerable length we prefer to
employ two rollers pressing on opposite sides so as to prevent flexure of the mandril
by pressure on one side only.
When the mandril is of very thin metal, we can dispense with the rolling
operation above described, and loosen the tube deposited on it by exhausting the
air from the interior of the mandril thus causing it to shrink. Or, before depositing
metal on the mandril we close its ends tightly and charge it with compressed air so
as somewhat to expand it, and then, after a tube has been deposited upon it, we

page_text: relieve the internal pressure, thus allowing the mandril to contract and leave
the tube deposited on it loose.
Dated this 92nd dox of March 1801
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improvement in the Manufacture of Tubes by Electrolysis.
We, FRANCIS EDWARD ELMORE, and ALEXANDER STANLEY ELMORE, both
of Spring Grove, Hunslet, Leeds, in the County of York, Electrometallurgists, 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 :-
For the manufacture of tubes by electrolysis as described in former Specifica-
tions as in No. 4499 of 1885, No. 8707 of 1885, No. 11,800 of 1885, No. 15,831
of 1886 and others a mandril, operating as a cathode is caused to revolve in an
electrolytic bath in which there is an anode of the metal to be deposited, and the
anode and cathode being connected to a source of electricity, the metal as it is
deposited on the mandril is rendered dense, compact and homogeneous in structure
by a burnisher pressing against it and travelling to and fro longitudinally while the
mandril revolves. Sometimes the burnishing tool is in the form of a roller made
to revolve with a surface speed differing from that of the mandril so as to rub as
well as roll on the surface of the deposited metal; a good effect is however
produced by the use of a rod of agate or equivalent hard mineral having its end of
small area pressed against the surface of deposited metal.
When the metal has been deposited to the desired thickness on the mandril it has
to be removed in the form of a tube.
Our present invention relates to the preparation of suitable mandrils and means
of facilitating the removal of electrolytically deposited tubes from the mandrils on
which they are deposited.
To form the mandril, we select a sound smooth tube, preferably one that has
been itself electrolytically deposited with continuous burnishing, and having got the
tube as truly straight and circular as possible and mounted it centrally on an axis,
we expose
it for a short time to the air by which a thin film of oxide is formed
upon its surface or we wash it with a sulphide solution or coat it with a thin
solution of wax in alcohol or otherwise treat it in any known manner to prevent
adhesion of the deposited metal to it. We then immerse it in the bath causing
it to revolve therein with a burnisher moving along it in the usual way, until a
thin shell of metal is deposited on it. We then substitute for the burnisher
a narrow roller which is pressed against the deposited metal and is, like the
burnisher, caused to travel along it, but not quite to one of the ends. This has
the effect of slightly stretching the deposited shell circumferentially and loosening
it from the mandril. During the subsequent depositing process which may be
continued for the required time to produce a deposit of desired thickness, the
looseness on the mandril remains as at first produced by the action of the roller,
and when the deposit is completed it is only necessary to part off and remove the
narrow band of metal at the one end which had not been loosened by the roller,
and then the tube can be readily slid off the mandril. For loosening the shell on
a mandril of considerable length we prefer to employ two rollers pressing on
opposite sides, or several rollers equally spaced round the mandril so as to prevent
flexure of the mandril by pressure on one side only.
When the mandril is of very thin metal we can dispense with the rolling
operation above described and loosen the tube deposited on it by exhausting the air
from the interior of the mandril, thus causing it to shrink from the shell deposited

page_text: on it. Or, before beginning to deposit metal on the mandril, we close its ends
tightly and charge it with compressed air so as somewhat to expand it, and then,
after a tube has been deposited upon it, we relieve the internal pressure, thus
allowing the mandril to contract and leave the tube deposited on it loose.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In the manufacture of tubes by electrolysis the herein described method of
loosening a tube deposited on a mandril, by subjecting the thin shell first deposited
to the pressure of a roller thus stretching all of it except a part at the end, so that
after depositing to required thickness and parting off the unstretched part, the tube
can be removed.
.
2. The method of loosening a tube deposited on a thin hollow mandril by
exhausting air from the mandril and thus causing it to shrink from the tube deposited
upon it.
3. The method of effecting the loosening of a tube deposited on a tubular mandril
by subjecting the mandril to internal pressure before depositing upon it, and after
deposit relieving the pressure within the mandril so that it shrinks from the tube
deposited upon it.
Dated this 21st day of January 1892.
ABEL & IMRAY,
Agents for the Applicants.