Year: 1886

page_text: Date of Application, 4th Nov., 1886
Complete Left, 27th July, 1887.
Complete Accepted, 30th Aug., 1887..
We, ROBERT WEBBER LINDSAY of George Street Birmingham and WILLIAM
DARWEN of George Street Birmingham Engineers do hereby declare the nature of
this invention to be as follows:-
We take copper as pure as is practically attainable and melt it under cover
in a plumbago crucible to just below boiling point. Immediately that it has
attained this temperature we pour it into a pouring crucible at the bottom of
which phosphorous has been placed so as to phosphorize the metal. The phosphorized
copper is then poured into a seamless cylindrical mould containing a central core.
The foundation of the core we use is an iron tube coated with ordinary moulding
sand or first with fibrous bands and then with moulding sand and afterwards
with a thinner coating of a solution or paste of calcined bone ash china earth
and asbestos which we apply by dipping the core into a trough containing the solution
or paste.
In this way a core both air and fireproof is obtained which enables us to obtain a
perfectly sound casting. The inside of the mould we cover with a thick coating of
tallow and china clay so as to prevent the copper from coming into contact with the
iron of which the body of the mould is composed.
The hollow copper castings thus obtained are heated in an ordinary furnace and
then slipped on to round bars or mandrils of iron or steel and rolled hot to say for
small tubes about half the original thickness of the metal in grooved rolls. The
amount of reduction depending on the size of the castings and of the tubes to be made
therefrom. The rolling down produces a projecting fin along two opposite sides this
is removed by drawing the tube through a hole with fixed cutters at the sides to
remove these fins. Afterwards the tubes are drawn off the mandrils which have been
covered with a thick covering of pounded charcoal made into a paste to prevent
adherence of the copper to the mandril. The tubes are then finished by the ordinary
methods of drawing.
T
1
1000

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Tubes of Copper or Alloys of
Copper.
We, ROBERT WEBBER LINDSAY of George Street Birmingham Managing Director
of Brass Rolling Mills and WILLIAM DARWEN of George Street. Birmingham Mill
Manager 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:
We take copper as pure as is practically attainable and melt it under cover in a
plumbago crucible to just below boiling point. Immediately that it has attained this
temperature we pour it into a pouring crucible at the bottom of which phosphorus has
been placed so as to phosphorize the metal. The phosphorized copper is then poured
into a seamless cylindrical mould containing a central core.
The foundation of the core we use is an iron tube coated with ordinary moulding
sand or first with fibrous bands and then with moulding sand and afterwards with a
thinner coating of a solution or paste of calcined bone ash china earth and asbestos or
of china earth and asbestos alone which we apply by dipping the core into a trough
containing the solution or paste.
In this way a core both air and fireproof is obtained which enables us to obtain a
perfectly sound casting. The inside of the mould we cover with a thick coating of
tallow and Chinese clay so as to prevent the copper from coming into contact with the
iron of which the body of the mould is composed.
The hollow copper castings thus obtained are heated in an ordinary furnace and then
slipped on to round bars or mandrils of iron or steel and rolled hot in ground
rolls to say for small tubes about half the original thickness of the metal. The
amount of reduction depending on the size of the castings and of the tubes to be made
therefrom. Afterwards the tubes are drawn off the mandrils which have been
covered with a thick covering of pounded charcoal made into a paste to prevent
adherence of the copper to the mandril. The tubes are then finished by the ordinary
methods of drawing.
In order that our invention may be fully understood and readily carried into effect
we will describe in detail the manner in which we prefer to proceed.
For phosphorizing the copper we ordinarily prefer to use from too of a per
cent of phosphorous that is to 100 lbs. of copper we should add say th of a lb. of
phosphorus. Preferably we place the phosphorus in the pot before pouring the copper
on to it as above described but other ways of adding the phosphorus to the copper
might be adopted.
To form the core of a mould say for making a seamless copper tube 12 inches outside
diameter we proceed as follows:-
We take an iron tube about 1" diameter that has been perforated with holes, and
upon its surface we wind hay, and increase its diameter to 2 inches, and upon this lay

page_text: sand that has been ground with water and about 10% of horse dung to a proper
consistency and prepared in the ordinary way for moulding and increase its diameter
to 28 inches. We then place it in a drying stove for twenty four hours; and at the
expiration of this time we add another layer of sand that has been twice ground and
again increase the diameter of the core to 2 inches-it is now again placed in the
drying stove for another twenty four hours, when it is taken out, to receive its final
coating consisting of a mixture of Chinese clay and asbestos preferably in equal
proportions, and when it has been placed in the drying stove for about eighteen hours
it is ready for placing in the ingot mould.
The ingot mould we use is shown in vertical section, side elevation and plan at
Figures 1, 2 and 3 of the drawings hereunto annexed-an elevation of the core is
shown at Figure 4. The ingot mould is a cast iron cylinder A accurately bored to a
diameter of 44 inches, through its whole length, and in the centre of this is placed the
coro B that is held in its position by collars or "bits " C accurately turned to fit the
inside of the ingot mould, these collars or "bits" being bored with a hole 11" diameter,
through their centres, to hold the ends of the core bar, in position in the centre of the
ingot mould and before the core is placed in position in the centre of the ingot mould, the
inside of the mould is coated with a mixture of Russian tallow and Chinese clay in
equal proportions, the core is now fixed tightly in position, in the centre of the ingot,
and we pour in the necessary quantity of copper prepared as previously explained and
when the casting is sufficiently set we remove the collars or bits at either end of the
mould and draw out the copper shell (which is now 43 inches diameter) and knock out
the core; the casting is now taken to the tube mill, where it is placed in a muffle, and
heated to a proper temperature, and between its passage from the mouth of the muffle
to the grooved rolls. We place inside the shell or tube a steel bar 2 inches diameter
and roll it between graduated grooved rolls, and reduce its diameter in one operation
to 33 inches, the bar is then removed, and in the usual way with four sets of steel
mandrills and dies, we reduce the tube (annealing when necessary) to its required
diameter of 14 inches. If fins are produced in the rolling operation they can be cut
off by circular saws or in other convenient manner before finally drawing the tube
down through dies in a cold state.
In place of rolling the tube down upon a loose bar or mandril as above described it
may be rolled on a stationary mandril as will be well understood.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :-
1. In the manufacture of tubes of copper alloy first casting a tubular ingot of
phosphorized copper in a cylindrical mould coated internally with tallow and Chinese
clay or equivalent composition and having within it a core formed of a perforated iron
tube surrounded with a coating of sand or first with hay or fibrous material and then
with sand and afterwards with a composition of Chinese clay and asbestos and then
rolling down the tubular ingot when in a hot state and finally drawing it down through
dies substantially as described.
2. The manufacture of copper or alloys of copper substantially as herein before
described.