Improvements in the Manufacture of Tubes from Sheet Metal.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Tubes from Sheet Metal.
We, FRANK IORNS GIBBS and WILLIAM WRIGHT, trading together as Gibbs &
Wright, of 70, Lower Hurst Street, in the City of Birmingham, Tinplate Workers
and Metal Workers, do hereby declare the nature of this Invention to be as
follows
This Invention consists of the hereindescribed improvements in the manufacture of
tubes from sheet metal. By our Invention we are enabled to produce metallic tubes
suitable for the frames of bicycles and other velocipedes and for other purposes
which will be strong and much less expensive than the cold drawn seamless steel
tubes usually employed.
According to one. arrangement of carrying out this Invention we take an open
jointed tube formed from a parallel strip of sheet steel or other suitable metal in
any well known manner like the inside open jointed tubes which are used for cased
brass tubes. This tube is by preference tinned inside and out either by being
made from tinned sheet metal or by being tinned after being bent into the tube as
aforesaid. We provide a strip of metal which is soldered or brazed along the joint
inside the tube so as to overlap the joint. We thus form a tube which is perfectly
cylindrical on the outside and which by having the joint made as above described
is comparatively strong. To facilitate soldering or brazing of the said strip along
the joint inside the tribe, we prefer to use another tube or rod of semi-circular or
other convenient form which is inserted in the tube so as to partly fill the same. The
space between this inner tube and the said strip is then filled and rammed in with
carbon or other suitable material to keep the strip in contact with the joint whilst
the same is being brazed or soldered! After the brazing or soldering operations the said
inner tube is withdrawn and the carbon or like material falls out. Or we may keep
the strip in position by fitting it in a longitudinal groove in a wooden core which is
inserted in the tube and may either remain there or be removed after the
soldering.
.
The said strip which is.soldered or brazed inside the tube may be of any width
that is to say the strip may either be a narrow strip so as to just overlap the joint or
the said strip may be considerably wider so as to extend partly around or quite
around the inside of the tube the edges meeting at the opposite side of the tube. In
this case the tube will be really formed of two open jointed tubes fitting telescopi-
cally one within the other. Both the inside tube and the outside tube are by
preference made of tinned sheet steel so that when they have been drawn or other-
wise bent to the tubular form and inserted one within the other they can be dipped
into a tinning bath or be placed in hot moulds in a muffle or be otherwise heated so
as to melt the tin and cause their adjacent surfaces to stick together and thus form a
strong tube. In the same manner when extra strength is required, we may make
the said tube of more than two open jointed tubes fitting one within the other and
sweated together as stated above.
In a modification of this Invention, instead of the outside and inside tubes being

page_text: each made of one strip of metal bent into the tubular form as stated above, the
said outside tube and the inside tube or tubes may each be made of two or more
strips of metal which are drawn. or otherwise bent to form a portion of the circle
and which when placed together make the complete tube of two or more thicknesses
of metal which are held together by any convenient means while they
are heated and sweated together. The said tubes may if preferred be strengthened
by an inner wooden core; and instead of or in addition to the wooden core the tubes
may the strengthened at one or more parts by having one or more internal tubular
rings soldered or otherwise fixed within them and around which the various strips
of metal of which the tube is formed are placed and secured and the whole sweated
together.
The moulds above referred to are made in two or more parts and have internally
the form of the tube and they serve the purpose of cramping the parts of the tube
together whilst it is being sweated in the muffle or on a hot plate or by other
means,
D
Desember 1908
COMPLETE SPECIFICATION..
Improvements in the Manufacture of Tubes from Sheet Metal.
We, FRANK IORNS GIBBS and WILLIAM WRIGHT, trading together as Gibbs and
Wright, of 70, Lower Hurst Street, in the City of Birmingham, Tinplate Workers
and Metal Workers, 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-
This Invention consists of the herein described improvements in the manufacture
. of tubes from sheet metal. By our Invention we are enabled to produce metallic tubes
suitable for the frames of bicycles and other velocipedes and for other purposes
which will be strong and much less expensive than the cold drawn seamless steel
tubes usually employed.
We will describe this Invention by referring to the accompanying drawings on
which
Fig. 1 is a cross section of a tube constructed according to this Invention;
Figs: 2 and 3 shew parts of the said tube separately;
Figs. 4 and 5 illustrate a method of holding the parts of the tube together
during the process of soldering;
Fig. 6 is a oross section shewing another method of holding the said parts together
by means of a wooden mandril which latter is shewn separately in section and in
elevation by Fig. 7;
Fig. 8 is a modified form of our improved tube;
Fig. 9 is a cross section of another form of tube constructed in accordance with
this Invention and
Fig. 10 shews parts of the tube represented in Fig. 9 separately in end' view and
Fig. 1 is a longitudinal view of one of the said parts.
The same letters of reference indicate the same or corresponding parts in all the
figures of the drawings.
According to one arrangement of carrying out this Invention as illustrated by
Figs. 1, 2, 3, 4 and 5, we take an open jointed tube A, such as shewn by Fig. 2,
formed from a parallel strip of sheet steel or other suitable sheet metal in any well
known manner like the inside open jointed tubes which are used for cased brass tubes.

page_text: The open joint of the tube is marked a². This tube is by preference tinned inside
and outside or tinned after it has been bent into the tube as aforesaid. We provide
a strip of metal B, shewn separately in end elevation and in side view by Fig. 3,
which as shewn in the end view is bent to the curve of the tube and then placed
inside the tube A so as to overlap the joint a¹ and soldered or brazed thereto."
thus form a tube such as shewn by Fig. 1 which is perfectly cylindrical on the outside
and which, by having the joint made by the separate strip B as above described, is
comparatively strong.
To facilitate the soldering or brazing of the strip B along the joint a inside the
tube as aforesaid, we prefer to use another tube or rod such as C (see Fig. 5) of seini-
circular or other convenient forin which is inserted in the tube A so as to partly fill
the same. The space D between this inner tube C and the strip B is then filled and
rammed in with carbon or other suitable material to keep the strip B in contact with
the joint a whilst the same is being tinned or soldered. After the brazing or
soldering operations the said inner tube C is withdrawn and the carbon or like material
falls out. Or as represented by Fig. 6 we may keep the strip B in place by fitting in
a longitudinal groove el in a wooden core E (shewn separately by Fig. 7) which
latter is inserted in the tube A and may either remain there or be removed after the
soldering.
The strip B which is soldered or brazed inside the tube A as aforesaid may be of
any width, that is to say, the strip B may either be a narrow strip so as to just
overlap the joint as represented by Fig. 1, or the strip B may be considerably wider
so as to extend partly around or quite around the inside of the tube A as represented
for instance in Fig. 8 the edges meeting at 1 opposite the joint al in the outer
tube A. In this case the tube will be really formed of two open jointed tubes A
and B fitting telescopically one within the other. Both the outside tube A and the
inside tube or strip Bare by preference made of tinned sheet steel so that when
they have been drawn or otherwise bent into the tubular form and inserted one into
the other as aforesaid they can be dipped into a tinning bath or placed in hot moulds
in a muffle or be otherwise heated so as to melt the tin and cause their adjacent
surfaces to stick together and thus form a strong tube. In the same manner when
extra strength is required, we may make the said tube of more than two open jointed
tubes fitting one within the other and sweated together as stated above.
In a modification of this Invention instead of the outside and inside tubes being
each made of one strip of metal bent to the tubular form as above described with
reference to Fig. 8, the outside tube A and the inside tube or tubes may each be made of
two or more strips of metal which are drawn or otherwise bent to form a portion of
the circle as shewn for instance by Fig. 10 where the outside tube is made of two
strips of metal marked respectively A A which are drawn or otherwise bent to form
a portion of a circle and the inside of the tube is made of the two strips B' B' which
are also drawn or otherwise bent to form a portion of the circle and fit within the
strips A As so that when these four strips A¹ A B B are placed together as shewn
in Fig. 9 they will make the complete tube of two thicknesses of metal (or there
may be more than four strips so as to form the tube of more then two thicknesses of
inetal) which are held together by any convenient means whilst they are heated and
sweated together. The said tubes may if preferred be strengthened by an inner
wooden core; and instead of or in addition to the wooden core the tube may be
strengthened at one or more parts by having one or more internal tubular rings such
as F see Fig. 10 soldered or otherwise fixed within them and around which the
various strips of metal of the tube is formed are placed and secured by screws or
other convenient means and the whole sweated together.
The moulds above referred to such as for instance as shewn in cross section by
Fig. 12 are made in two or inore parts and have internally the form of the tube and
they serve the purpose of cramping the parts of the tube together whilst it is being
sweated in the muffle or on. a hot plate or by other means.
It will be understood that our Invention is similarly applicable to the manufacture
of tubes of other sections than round. For instance, Fig. 13 shews a D-section-tube

page_text: made in accordance with our Invention the strip B in this case is by preference made
flat and of the same width as the flat side of the tubo.
Fig. 14 shews another form of D-tube made in accordance with this Invention
where the outside tube A and the inside tube B are both open jointed D-tubes
the one being slided into the other and there secured by soldering or brazing or
other ineans.
Having now particularly described and ascertained the nature of our said' Inven-
tion and in what manner the saine is to be perforined, we declare that what we
clain is :-
1. The improved tube consisting of a so called "open jointed" sheet metal tube A
having a strip of metal B soldered or brazed or otherwise similarly fixed on the
inside to cover and strengthen the joint substantially as herein before described and
illustrated by Figs. 1 and 13 of the accompanying drawings.
2. The improved tube consisting of two or more so called "open jointed" sheet
metal tubes fitted and soldered or brazed or otherwise similarly fixed one within
the other or others so as to form a tube of two or more thicknesses of metal
substantially as herein before described with reference to Figs. 8 and 14 of the
accompanying drawings.
3. The improved tube consisting of the combination of a so-called "open jointed "
sheet metal tube A, a strip of metal B soldered or brazed or otherwise similarly
fixed on the inside to cover and strengthen the joint and the internal wooden core.or
mandril E fitted in said tube to strengthen the same substantially as hereinbefore
described.
4. The improved tube consisting of several sheet metal parallel strips drawn or
otherwise bent to conform in cross section with a portion of the tube the said strips
being fitted and soldered or brazed or otherwise similarly fixed together so as to
form a tube of two or more thicknesses of metal with the joints of one thickuess
being overlapped by the strips forining the next thickness of metal substantially
as herein before described with reference to Figs. 9, 10 and 11 of the accompanying
drawings.
Duted this 17th day of Santambar 1807