Improvements in the Manufacture of Tubes or Seamless Hollow Wire.
Year: 1890

page_text: Date of Application, 28th Oct., 1890-Accepted, 3rd Jan., 1891
Improvements in the Manufacture of Tubes or Seamless Hollow
Wire.
I, CHARLES ROBINSON SMITH of 481 Pine Street, Providence, Rhode Island, United
States of America, Manufacturing Jeweller, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
lescribed and ascertained in and by the following statement :-
My invention relates to the manufacture of tubes of metal or plated metal,
commercially known as "hollow wire" and adapted for the manufacture of pencil
cases, various kinds of jewellery, and for other purposes.
My improved process consists in drawing up a sheet of metal into the form of a
longitudinally split tube or shell, placing the same upon an arbor which has adjustable
sleeves capable of being fastened in position upon said arbor, the shell being located
on the arbor between the sleeves, then passing the tube and arbor through the flame
of blow pipes and fusing the metallic shell upon the arbor so as to flow the edges of
the longitudinal opening together, then drawing the shell which has been so fused
(while still in position upon the arbor) through a draw-plate to give the exterior
surface a smooth finish, and then after removing the sleeves, drawing off the fused
tube from the arbor; or if a plated hollow wire is desired, the split tube so placed
upon the arbor is of one kind of metal, and is covered with borax or other fluxing
material and a similarly split tube of another kind of metal is slipped over the former
tube and the two are fused together, drawn, and removed from the arbor as above
described.
In the accompanying drawings
Figure 1, is a sile elevation of the arbor upon which the hollow wire is formed.
Figure 2, is a perspective view of the split metallic shell which is to be made into
seamless bollow wire.
Figure 3, is a cross-section of the same on the line ..
Figure 4, shows in side elevation the split shell in position upon the arbor.
Figure is a perspective view of the seamless hollow wire which is the product of
my invention.
Figure 6 is a cross section of the same on the line...
Figures 7, 8, 9, 10, 11 and 12, illustrate the process when the hollow wire is to be
plated with another metal.
Figure 7, shows in perspective a split metallic shell.
Figure 8, is a cross section of the same on the line x, .
Figure 9, is a perspective view of the split metallic shell in position upon a split
shell of another metal.
Figure 10, is a cross section of the same on the line.
Figure 11 is a perspective view of the seamless plated hollow wire.
Figure 12, is a cross section of the same on the line ., .
Figure 13 is a side elevation of a modified form of the arbor.
Like letters of reference indicate corresponding parts in the several figures.
A is an arbor, made of any suitable material, preferably of steel, B B are sleeves
fitting loosely on the arbor and capable of longitudinal adjustment thereon at any
desired position, and are fastened in such position by the set screws (C. A strip of
metal is drawn up by means of a draw-plate or in any other suitable manner into the
form of a split tube D, having a longitudinal opening a. as shown in Figures 2 and 3.
One of the sleeves B is removed from the arbor A and the arbor is covered with oil
or other substance to prevent the adhesion of the metal which is to be heated in
position upon it, as hereinafter described. The split tube D is then placed on the

page_text: arbor, as illustrated in Figure 4, and the sleeves B B are brought up to abut the tube
on each side respectively, and there fastened in position by the screws CC. The tubo
is thus immovably held.in place during the operation which is to follow.
The arbor A and the split tube D therein, are now passed horizontally through the
flame of one or more blow-pipes, or may be heated in a furnace, or in any suitable
manner, to such a degree as to melt and fuse the split, tube D sufficiently to flow the
edges of the opening a together and to make the tube D seamless throughout its
entire length.
No fluxing material should be used between the tube D and the arbor A, or
otherwise the shell D would be soldered or united to the arbor within it.
The arbor should be made of such metal as will not amalgamate with the shell by
being subjected to heat.
The arbor with the tube upon it should be fed to the flame by a longitudinal and
rotary movement. Any suitable mechanism may be used which will revolve the arbor
and tube and at the same time advance them longitudinally through the flame, or they
may be manipulated by hand, or otherwise suitably subjected to the heat.
When the shell or tube has been thus fused, it is desirable to give it a smooth
exterior finish by drawing it, still upon the arbor, through a draw plate in the usual
manner.
The tube is then removed from the arbor by unfastening and taking off one of the
sleeves and then, by placing one of the butt ends of the tube against a draw-plate, the
arbor can be pulled out of the tube. The product of this process is the hollow wire
shown in Figure 5. If it is desired to reduce the hollow wire to a smaller diameter, it
can be done by drawing it down successively on other arbors of less and less diameters,
through a draw-plate, in the well known manner.
Instead of closing the opening a of the split shell or tube as above described, it
may be closed by soldering, and the soldered tube can then be brazed down on the
arbor by passing it through the heat, as above explained, and afterwards drawn off
from the arbor.
If the hollow wire is to be a plated wire, as, for example, a gold-plated hollow
wire, I use in addition to the above process the following: A split shell E of gold, is
drawn up like the shell D except that it should be of a diameter sufficiently great to
slip over the tube D. It has a longitudinal opening e. The outer surface of the
tube of inferior metal, is covered with borax or a proper fluxing material and the
tube E is then slipped over the tube D, as shown in Figures 9 and 10, so that
the openings a and è are diametrically opposite each other. Care should be taken that
no flux gets between the arbor and the tube D. The compound tube D E is then
put on the oil-covered arbor, fastened thereon by the sleeves and screws and subjected
to heat, as before described. so that the edges of the openings a, e are fused together.
The tube is then polished and removed as aforesaid, the product being a gold-plated
hollow wire, which may be reduced in diameter as already specified.
Instead of forming a split tube E of gold, as aforesaid, 1 may use a solid tube of
gold formed in any of the well known methods. I do not confine myself to any
specific manner of forming the tubes D E as the essential feature of my invention is
fusing a metallic tube of any other sort, to produce a seamless plated hollow wire.
The arhor may in some cases be dispensed with, if the tube is to be thus plated,
because only a sufficient degree of heat is required to melt the gold so as to fill the
openings a and ein which case the inner tube is less exposed to the heat and is of a
comparatively less temperature, as its interior space is accessible to the air, so that
said inner tube may have sufficient rigidity not to bend during the process. In this
case the inner tube itself serves the essential purposes of the arbor, but the use of the
arbor is preferable as it insures stiffness and accuracy of work.
In Figure 13 1-show a modified form of the arbor which is slightly tapered to
facilitate the withdrawal of the tube. If such an arbor is used, the product will
itself be tapered, but it can be reduced to a straight wire by drawing it on a smaller
straight cylindrical arbor in the usual manner.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is
First. The improved process of manufacturing hollow wire herein described,
consisting in the formation of a longitudinally split metallic tube, the use of a
steel arbor having short metallic sleeves, covering said arbor with oil, placing said
tube upon said arbor with said sleeves abutting the ends of said tube respectively,
passing said tube, arbor and sleeves, horizontally with a rotary and longitudinal
movement through the flame of blow-pipes so as to melt said tube sufficiently to fuse
its split edges together drawing said tube when cold and so in position through a
draw-plate for a finish, withdrawing said sleeves and removing the tube from the
arbor substantially as specified.
Second. The improved process of manufacturing hollow wire herein described,
consisting in the formation of a longitudinally split metallic tube, the use of a steel
arbor covered with oil, placing the tube on the arbor, passing said tube and arbor
horizontally with a rotary and longitudinal movement through the flame of blow
pipes so as to melt said tube sufficiently to fuse the split edges together, drawing
said tube so in position through a draw-plate for a finish and withdrawing said tube
from said arbor, substantially as specified.
Third. The improved process of manufacturing seamless plated metallic hollow
wire, herein described, consisting in the formation of a longitudinally-split tube of
metal, the formation of a longitudinally-split tube of another metal, but of a slightly
greater diameter than the diameter of the first mentioned tube putting a fluxing
inaterial upon said first mentioned tube, placing the larger tube upon the other tube,
placing this compound tube upon an arbor covered with oil, subjecting said tubes
while so in position to heat sufficient to fuse the outer tube upon the inner tube and
finishing the compound tube by drawing it through a draw-plate or in any known
manner, substantially as specified.
Fourth. The improved process of manufacturing seamless plated hollow wire
herein described, consisting in the formation of a longitudinally split tube of metal,
the formation of a longitudinally split-tube of another metal but of a slightly greater
diameter than the diameter of the first mentioned tube, putting a fluxing material
upon said first mentioned tube, placing the larger tube upon the other tube, subjecting
said tubes while so in position to heat sufficient to fuse the outer tube upon the inner
tube and finishing the compound tube by drawing it through a draw plate or in any
known manner, substantially as specified.
Fifth. The improved process of manufacturing seaniless plated hollow wire herein
described, consisting in the formation of a longitudinally-split tube of metal the
formation of a longitudinally split tube of another metal but of a slightly greater
diameter than the diameter of the first mentioned tube, putting a fluxing material
upon the first mentioned tube, placing the larger tube upon the other tube so that the
openings of said tubes shall not be radially coincident subjecting said compound tube
to heat sufficient to fuse the outer tube upon the inner tube and at the same time to
flow the melted metal into said openings to close the same and finishing the
compound tube by drawing it through a draw plate or in any known manner
substantially as specified.
D
220
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.