IMPROVEMENTS IN THE MANUFACTURE OF METAL TUBES
Year: 1876

page_text: LETTERS PATENT to William Sumner, of Salford, in the County of Lancaster,
and Eric Hugo Waldenström, of the same Place, Engineers, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF METAL TUBES."
Sealed the 28th April 1876, and dated the 14th January 1876.
PROVISIONAL SPECIFICATION left by the said William Sumner and Eric
Hugo Waldenström at the Office of the Commissioners of Patents on the 14th
January 1876.
WILLIAM SUMNER, of Salford, in the County of Lancaster, and ERIC HUGO
WALDENSTRÖM, of the same Place, Engineers. "IMPROVEMENTS IN THE MANU-
FACTURE OF METAL TUBES."
Our Invention is particularly beneficial in manufacturing seamless copper tubes
for multitubular boilers, but it may be applied in manufacturing tubes for other
purposes.
In performing our Invention we cast a polygonal or cylindrical ingot with a hole
made by a metal, sand, or other core, or the ingot can be cast solid and then bored
out, the ingot is then heated and placed on a cold or slightly heated mandril, after
which it is rolled down in an ordinary rolling mill, or it is passed through a series
of grooved rolls placed so that the tube passes in a straight line from one set of
rolls to the other. All the rolls are connected together by gearing, and work at a
gradually accelerating speed proportionate to the reduced area of the section.
It may be necessary in order to produce a perfect tube to turn and forge the
ingot before rolling. When the tube thus produced has arrived near to the ultimate
thickness required it is passed through rolls to loosen the mandril, which is then
drawn out, and the tube is finished by drawing through one or more suitable dies
of the usual construction. By this means solid tubes can be manufactured with
less hand labour and fewer heats than usual, consequently more economically and
with less injury to the metal than heretofore.
The ingot may be cast with a small hole and then bored out to an enlarged size
by a crown drill. The hollow cylinder thus bored out may then be used for manu-
facturing tubes by rolling down when heated with or without a mandril.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Sumner and Eric Hugo Waldenström in the Great Seal Patent
Office on the 8th July 1876..
WILLIAM SUMNER, of Salford, in the County of Lancaster, and ERIC HUGO
WALDENSTRÖM, of the same Place, Engineers. " IMPROVEMENTS IN THE MANU-
FACTURE OF METAL TUBES."
Our Invention is particularly beneficial in manufacturing seamless copper tubes
for multitubular boilers, but it may be applied in manufacturing tubes for other
purposes; and it consists in an improved mode of manufacturing seamless copper
tubes whereby labour is economised and fewer heats are required than heretofore.
In performing our Invention we cast a polygonal or cylindrical ingot with a hole
made by a metal, sand, or other core, or the ingot can be cast solid and then bored
out; it is then ready to be rolled, or it may be forged and turned before rolling.
The ingot is then heated and placed on a cold or heated mandril, after which it is
rolled down in an ordinary two or three high rolling inill, or it is passed through
a series of grooved rolls placed so that the ingot or tube passes in a straight line
froin one set of rolls to the other, as shewn in Figs. 1 and of the accompanying
Sheet of Drawings, in which a, b, c, and d, represent four pairs of rolls which are
supported in ordinary framing and connected together by gearing. These rolls are
shewn in Fig. 2 with only one groove in each, but the number of grooves may be
increased, and the number of pairs of rolls forming the series may also be
varied.
The grooves are gradually reduced in diameter so that the ingot may be
elongated in passing between them. The mandril e is provided with a porter bar f
by means of which the ingot can be turned about one-fourth round after it has
passed between one pair of rolls and before it enters the succeeding pair.
Fig. 3 represents a series of rolls which may be used instead of the rolls shewn
in Figs. 1 and 2. In this arrangement the rolls are placed alternately in a hori-
zontal and a vertical position, as now customary in rolling rods for making wire; by
this arrangement the porter bar for turning the mandril may be dispensed with.
All these rolls are connected together by gearing, and work at a gradually accele-
rating speed proportionate to the reduced area of the section. The tube. thus
produced is removed from the mandril on an ordinary draw bench or other suitable
apparatus, and it is finished by drawing cold through one or more suitable dies of
the usual construction. By this means solid tubes can be manufactured with less
hand labour and fewer heats than usual, consequently more economically and with
less injury to the metal than heretofore.
The ingot may be cast with a small hole and then bored out to an enlarged size
by a crown drill. The hollow cylinder thus bored out may then be used for manu-
facturing tubes by rolling down when heated with or without a mandrill.
Having thus stated the nature of our Invention and described the manner of
performing the same, we wish it to be understood, that we make no claim to
the arrangements of the rolls except when used for the purpose set forth, and
wo claim

page_text: mandril between a series of rolls revolving at accelerated speeds, as shewn and
described in reference to Fig. 3.
In witness whereof, we, the said William Sumner and Eric Hugo Walden-
ström, have hereto set our hands and seals, this Sixth day of July, One
thousand eight hundred and seventy-six.
W. SUMNER.
(L.S.)
E. H. WALDENSTROM.
(L.S.)