IMPROVEMENTS IN THE MANUFACTURE OF METAL TUBES OR TUBULAR ARTICLES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Alfred Vincent Newton at the
Office of the Commissioners of Patents, with his Petition, on the
11th June 1875.-A communication from George Jones Brooks, of
Brattleborough, in the State of Vermont, United States of America.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lanc, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF METAL TUBES OR TUBULAR ARTICLES," to be as follows:-
This Invention relates to improvements on the Patent granted to me
and bearing date December 9th 1781. In the Specification of that
Patent a process is described of forming seamless tubes and tubular
articles from blocks of metal having a passage formed through them.
These blocks are reduced or drawn to the desired length by external and
internal pressure, due in part to the action of rolls and in part to the action
of a yielding corc. For this purpose a metal core shewing in cross
section a taper from its opposite edges to its centre is inserted within the
block, and the latter is exposed to side and edge rolling to reduce it to a
slab. The slab is then subjected to final rolling to open and finish or
shape it into the tubular articles desired.

page_text: In carrying out this process of reducing the block to a slab it is
necessary to use a set of rolls specially shaped to correspond with the
sectional form of core, and to graduate or to reduce the blocks by a
pro rata rolling. When operating however upon large blocks of metal
a modification of the process is found desirable.
It is now proposed to cast the hollow blocks with an opening nearly
approaching a rectangular figure to receive a core of corresponding form
and composed of wedge-shaped or tapering pieces. This will allow of
the employment of ordinary tongue and groove rolls. The core may
consist of two wedge-shaped pieces of a length equal to the length of the
hollow block, and of any desired breadth short of the whole width of
the opening; or it may be composed of three taper pieces laid together,
the centre piece tapering on both its edges. These constructions of core
while they admit of longitudinal extension with the block under the
rolling pressure, will offer no obstacle to their being removed when the
block has been reduced to the form of a slab.
Instead of the form of block shewn in the Specification above referred
to, it is proposed when manufacturing tubular articles of considerable
weight, and having, say, a two inch sectional thickness to cast the block
with parallel edges and with slightly arched faces, and to make the cores
correspond thereto. By giving the face of the rolls a correspondingly
hollow form they will be enabled to bring down the block to the form
of an oval slab without any change of form in the following rolls being
required.
In making the divided core it is preferred first to prepare one half or
portion thereof and to place it in a sand or other mould, and to form the
complement of the core by running molten metal into the mould. The
contact faces of the parts composing the core should be finished by
planing or otherwise to ensure a close fit; but to prevent adhesion to each
other as well as to the block or slab, the parts should be coated with
graphite before insertion into the block.