Improvements in Mandrels Used in the Manufacture of Welded Steel and Iron Tubes.
Year: 1896

page_text: Date of Application, 28th Feb., 1896
Complete Specification Left, 13th Nov., 1:96-Accepted, 19th Dec., 1895
PROVISIONAL SPECIFICATION.
PROVISIONAL SPECIFICATION.
Improvements in Mandrels Used in the Manufacture of Welded Steel
and Iron Tubes.
I, CHARLES EDWARD SMITII, of The Limes, Wood Green, Wednesbury, in
the County of Stafford, Manager of Brunswick Tube Works, Wednesbury
aforesaid, do hereby declare the nature of this invention to be as follows:-
In the ordinary method of manufacturing welded steel and iron tubes the trough
shaped skelps to be made into tubes are raised to a welding heat and are passed
through grooved rolls the grooves of which have the size and figure necessary to
weld together the overhanging edges of the heated skelp. The skelp is supported
internally by a bulb mandrel the bulb or enlarged part of which occupies the eye
of the rolls.
It occasionally happens that the bulb becomes fixed in the tube during
the rolling process and there is great difficulty in removing the inandrel from the
tube.
My invention has for its object to obviate the difficulty referred to and consists
in constructing the mandrel in the manner hereinafter explained.
In order that my invention may be the better understood remark that the
stem and bulb of the mandrel are ordinarily made in one piece and my invention
consists in constructing the bulb mandrel in several pieces connected together in
the ways hereinafter described, by which method of construction if the bulb
becomes fixed in the tube it can as hereinafter explained he readily removed
therefrom.
Instead of making the bulb and stem of the mandrel in one piece I make the
stem separate from the bulb and I make the bulb hollow and in several parts,
preferably four, the divisions in the bulb being in planes intersecting one another
in the axis of the bulb. The interior of the bulb is of considerably larger diameter
than the end of the stem and between the stem and the bulb is a holder in the axis
of which the stem enters and the exterior of which holder carries a series of
dovetail projections equal in number to the number of parts into which the bulb is
divided. In the interior of each part of the bulb of the maudrel is a dovetail
recess into which recesses the dovetail projections on the holder may be made
respectively to engage by a sliding motion.
The said dovetail projections and recesses are doubly inclined, that is, while
their sides are inclined to one another from their outer to their inner edges, the top
faces of the said projections and recesses are inclined from back to front.
The parts described are put together in the following manner.
The holder being placed upon the end of the stem the several parts of the bulb
are connected to the said holder by being passed on to the projections of the said
holder by a sliding motion. The external figure of the bulb is finished by turning
while the parts of the bulb are in position on the holder. The dovetail recesses in
the parts of the hollow bulb do not pass through the whole length of the bulb but
only extend to about two thirds its length and the dovetail projections have the
same length so that there are shoulders in the recesses in the parts of the bulb
which abut against corresponding shoulders formed by the ends of the dovetail
projections. The distance to which the parts of the bulb can slide upon the holder
is thus limited.

page_text: In case the mandrel becomes fixed while in use it is only necessary by the aid
of a rod or bar of iron to strike a few blows upon the end of the holder protruding
from the eye of the rolis. The holder is thereby made to retire a short distance
from the interior of the hollow bulb when the parts of the bulb collapse and may
be easily removed.
Instead of making the stem and the bulb holder separate as herein before described
they may be made in one piece.
Dated this Tanner rigt
1000
Improvements in Mandrels Used in the Manufacture of Welded Steel
and Iron Tubes.
1, CHARLES EDWARD SMITH, of The Limes, Wood Green, Wednesbury, in
the County of Stafford, Manager of Brunswick Tube Works, Wednesbury,
aforesaid, do hereby declare the nature of my invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement:-
In the ordinary method of manufacturing welded steel and iron tubes the trough
shaped skelps to be made into tubes are raised to a welding hent and are passed
through grooved rolls the grooves of which have the size and figure necessary to
weld together the overhanging edges of the heated skelp. The skelp is supported
internally by a bulb mandrel the bulb or enlarged part of which occupies the eyo
of the rolls.
It occasionally happens that the bulb becomes fixed in the tube during the
rolling process and there is great difficulty in removing the mandrel from the
tube.
My invention has for its object to obviate the difficulty referred to aud consists
in constructing the mandrel in the manner hereinafter explained.
In order that my invention may be the better understood I remark that the
stem and bulb of the mandril are ordinarily made in one piece and my invention
consists in constructing the bulb mandrel in several pieces connected together
in the ways hereinafter described by which method of construction if the bulb
becomes fixed in the tube it can, ns hereinafter explained, be readily removed
therefrom.
Instead of making the bulb and stem of the mandrel in one piece I make the
stem separate from the bulb and I make the bulb hollow and in several parts,
preferably four. The interior of the bulb is of considerably larger diameter than
the end of the stem and between the stem and the bulb is a holder in the axis of
which the stem euters and the exterior of which holder carries a series of dovetail
projections equal in number to the number of parts into which the bulb is divided.
In the interior of each part of the bulb of the mandrel is a dovetail recess into
which recesses the dovetail projections on the holder may be made respectively to
engage by a sliding motion.
The said dovetail projections and recesses are doubly inclined, that is, while
their sides are inclined to one another from their outer to their inuer edges, the top
faces of the said projections and recesses are inclined from back to front.
The parts described are put together in the following manner;-
The holder being placed upon the end of the stem the several parts of the bulb

page_text: are connected to the said holder by being passed onto the projections of the said
holder by a sliding motion. The external figure of the bulb is finished by turning
while the parts of the bulb are in position on the holder. The dovetail recesses in
the parts of the hollow bulb do not pass through the whole length of the bulb but
only extend to about two thirds its length and the dovetail projections have the
same length so that there are shoulders in the recesses in the parts of the bulb which
abut against corresponding shoulders formed by the ends of the dovetail projections.
The distance to which the parts of the bulb can slide upon the holder is thus
limited.
Figure 1 of the accompanying drawings represents in side elevation the acting
end of a bulb mandrel constructed according to my invention and Figure 2 is an
elevation of the larger end of the same with the stem or rod of the maudrel
removed; Figure 3 is a longitudinal section of the said mandrel and Figure 4 is a
cross section on the line z, Figure 1.
Figures 5, 6 and 7 represent respectively in side elevation, end elevation and
longitudinal vertical section the bulb holder of the mandrel detached and Figures 8
and 9 represent respectively in end and inside elevation one of the parts of the
bulb separately.
Figure 10 represents in longitudinal section, a bulb mandrel constructed
according to a modification of my invention hereinafter described.
The same letters of reference indicate the same parts in the several figures of
the drawings.
In constructing the bulb mandrel represented in Figures 1, 2, 3 and 4, I form
the stem or rod a of the mandrel separate from the bulb, the said stem or rod a
having a nose piece a² for receiving the bulb holder (see Figures 5, 6 and 7).
The said holder & consists of a short hollow conical tube having on its exterior and
at its back or larger end, preferably four, dovetail ribs or projections b', b1, b₁, b¹.
It will be seen by reference to Figure 3 that the top faces of the projections 6' 6'
follow the inclination of the conical holder b on which they are formed. I make
the bulb proper of four parts marked respectively e, e, c, e which when put
together for a hollow conoidal body. I form in the inner faces of the said
parts c, e, c, doubly inclined recesses (see the views of the part c¹ Figures 8
and 9) of a size proper to fit the ribs or projections 64 of the bulb holder b. When
the parts c', c, c, care passed from the smaller end of the holder onto the
projections the ends of the recesses abut against the shoulders of the said
projections which shoulders constitute stops for the bulb to bear against when
the mandrel is in use.
In case the mandrel becomes fixed while in use it is only necessary by the aid of
a rod or bar of iron to strike a few blows upon the end of the holder 6 protruding
from the eye of the rolls. The holder & is thereby made to retire a short distance
from the interior of the bollow bulb when the parts of the bulb collapse and may
be easily removed.
Instead of forming dovetail projections on a bulb holder of the kind bereiubefore
described and represented the said dovetail projections may be formed on the
end of the rod or stem of the mandrel the use of a separate bulb holder being
dispensed with.
This modification of my invention is represented in Figure 10.
The dovetail projections on the rod a are marked a¹ and the shoulders or stops
of the same are marked a. The nose a² of the stem is made of such a length that
it projects a short distance through the open front end of the bulb.
I wish it to be understood that although I have described and represented and
prefer to make the dovetail projections on the bulb holder or on the end of the
stem or rod of the mandrel and the dovetail recesses for engaging with the same
in the inner faces of the several parts of the bulb yet this arrangement may be
reversed, that is to say, dovetail projections may be formed on the inner faces of
the parts of the bulb for taking in dovetail recesses or slots in the bulb holder or
in the end of the stem or rod of the mandrel.

page_text: Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed declare that I claim as my
invention of "Improvements in mandrels used in the manufacture of welded steel
and iron tubes":-
Making the bulbs of bulb mandrels separate from the stems or rods of the said
mandrils and in several, preferably four, parts, which parts are held together or
kept in position on the end of the stem or rod of the mandrel by dovetail engage-
ments with a bulb holder on the nose end of the stem or rod of the mandrel or by
dovetail engagements with the ceud of the stem or rod of the mandrel substantially
ns and for the purpose hereinbefore described and illustrated in the accompanying
drawings.
Dated the Twenty-first day of October 1800
CHARLES EDWARD SMITH.