Improvements in the Manufacture of Tubes suitable for Use in the Construction of Velocipedes.
Year: 1891

page_text: COMPLI DI LULETATION.
Improvements in the Manufacture of Tubes suitable for Use in the
Construction of Velocipedes.
We, JOHN EARLE and GEORGE BOURNE both of Tube and Rolling Mill Works,
Hooper Street, Spring Hill, Birmingham, in the County of Warwick, Tube Manu-
facturers, 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 :-
Our invention relates to the manufacture of tubes and is chiefly designed to
provide an improved form of tube for use in the construction of the backbone and
other parts of velocipedes and which are usually formed hollow for the purpose of
obtaining strength combined with lightness.
A very considerable amount of tubing is usually employed in the construction of
the framework, back bone, handle bars, et cetera and various forms of tubing have
been used such as butt welded tube, ordinary brazed tube, and also tube of the kind
or class known in the trade as seamless or solid drawn steel tube, the latter being
largely employed where strength and flexibility are required. Owing however to
the high first cost of seamless or solid drawn steel tube and to the difficulty and
trouble of afterwards preparing the same for silver plating or nickel plating, it can
only be economically employed in the highest class of machines.
Now our invention has for its object to provide a tube possessing great strength,
and flexibility, which shall be cheap as regards first cost and which shall moreover
possess sufficiently good surface to allow of the same being plated with silver
or nickel without the necessity for preparing the same by grinding, filing, or the like.
In carrying our invention into practice we consider it advantageous to proceed
as follows:-
A strip of metal preferably of iron or steel is turned up into a tube the edges
being butted and then brazed in the usual manner thereby forming what is commonly
known as a brazed tube; a welded tube, a solid drawn tube, and embrazed or open
joint tube can be employed. This tube is now enclosed in a second or outer tube
consisting of a seamless copper tube which is drawn on to the first or brazed tube.
The combined tubes are now taken to a draw bench and passed successively through
suitable draw plates, dies or the like, the inner brazed tube and the outer seamless
copper tube being thus simultaneously reduced in diameter and being pressed or
forced very tightly together, thus forming a compound tube, the inner portion of
which preferably of steel or iron while the outer covering consists of copper.
The said composite tube thus possesses great strength and flexibility while the
outer portion thereof being of drawn copper possesses a close and even surface and
a silky appearance and requiring very little preparation for plating.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
The manufacture substantially in the manner hereinbefore described of a compo
site or compound tube consisting of an iron or steel inner tube surrounded by a solid
drawn outer covering of copper, or of brass or other suitable alloy for the purposes
specified.
Dated this 18th day of Morob 1801
J. EARLE,
By L W., per F. B.
G. BOURNE,
By L. W., per F. B.