Improvement in Machines for Reducing Tubes.
Year: 1892

page_text: Date of Application, 13th Apr., 1892-Accepted, 25th June, 1892
COMPLETE SPECIFICATION.
Improvement in Machines for Reducing Tubes.
I, SIDNEY OSBORNE BIGNEY of Attleborough, in the County of Bristol, in
the State of Massachusetts, 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 described and ascertained in and by the following
statement:-
My invention relates to machines for the manufacture of that class of metallic
tubes, commercially known as "hollow wire" and which is especially useful in the
jeweller's art.
I reduce the thickness of the tube by means of the hammer dies of a swaging
machine acting upon limited portions of the tube, consecutively while the tube is
filled by a metallic arbor, and employ means, substantially as hereinafter specified,
for feeding to the dies the tube to be reduced and for forcing it off the arbor, as
soon as reduced.
Great difficulty has heretofore been experienced in the manufacture of tubing on
account of the lack of any practical method of reducing its thickness and diameter.
In this manufacture, the tube, especially when plated or covered with gold, must
have at first a considerable thickness of stock and also a considerable diameter of
the bore. It is usual to form it in short sections or pieces, and then to pass it
through a draw-plate repeatedly, thus gradually reducing the thickness and diameter
and at the same time lengthening the tube.
To preserve the exact rotundity of the tube, a metallic arbor is inserted through
it, and the tube and arbor in this position are drawn through the draw-plate. The
result is that the tube is thus drawn upon the arbor so tightly as to frictionally
hold it thereon with great force. The tube is then removed from the arbor by
placing one of the butt ends of the tube against the draw-plate at an opening
therein, which is large enough to receive the end of the arbor, but which is too
small to receive the tube then by fastening the nippers of the draw-board to the
arbor, the latter is pulled out of the tube. The tube however, is liable to be
injured by such forcible withdrawal as the resistance comes wholly upon the
comparatively thin edge.
If the tube is long, the frictional engagement of it upon the arbor is so great
that it cannot be removed at all. To facilitate the stripping therefore, the tube,
when completed, must be in short sections.
It is the purpose of my invention to provide a simple and effective method of
reducing tubes which obviates these difficulties.
In the accompanying drawings:
Figure 1 is a plan of the apparatus adapted to reduce tubes according to my
improved process.
Figure 2 is a side elevation of the same, with the reducing mechanisın in central
vertical section.
Figure 3 is an enlarged view, partly in side elevation and partly in vertical
section, showing the tube and the enclosed arbor and the method of supporting the
same during the process and of presenting it to the dies.
Figure 4 is an enlarged view in elevation, as seen on line a x of Figure 2, and
looking in the direction indicated by the two arrows from said line.
Figure 5 is a cross section on line 2 2 of Figure 3.
Figure 6 is a sectional view on line of Figure 2.
A represents a swaging machine whose dies are shown at a, and the central
opening at b, and whose central tubular space is shown at c. The main shaft of

page_text: the swaging machine has an enlarged head or end v, which is transversely grooved
and the dies a are mounted in said groove and are movable therein by the pressure
of the rollers was the shaft turns. The face plate, through which the central
opening b, is formed is fastened to the enlarged head v of the main shaft by the
screws y. Upon the face of this machine, I arrange a plate B and fasten it in
position by means of a screw d.
21
C is a post or standard, having a plane top plate e. A shaft D is mounted in the
standard C and has at its outer end a wheel E rigidly secured thereto, which wheel
may be turned by a handle F as indicated in full lines, or be driven by power by
a belt, indicated in Figure 2, in dotted lines. The shaft D has a gear G upon it,
which engages with the cogged wheel H, the latter being fastened upon a shaft I,
which is mounted in the standard C as shown.
The shaft I is screw-threaded (see Figure 2) and at its inner end bears against the
plate B. A fixed guide rod J extends from the standard C to the plate B where
it is firmly held in place. A supporting bar K, having slots F near one end and
having its opposite end 9 bent and slotted is fastened to the top plate e of the
standard C by the screws h and thus is capable of a limited longitudinal adjustment.
A traveller L having two vertical plates, which are provided with the apertures i
and and are bolted together, as seen at k. I carries a clamp M, the details of
which are shown enlarged in Figure 4. This clamp consists of two curved
jaws m m pivoted together at n, so as to be capable of an opening and closing
movement.
Each jaw m has a concave inner screw-threaded surface o, adapted to engage
with the screw-threads of the shaft I and an extension p. To one of the extensions p,
a bent lever N is pivoted, as seen at 9 and a link O is pivoted to the other
extension p, as seen at and to the bent lever N as seen at s. By moving the
handle or bent lever N. in the direction indicated by the arrow in Figure 4 the two
jaws m. are closed so as to engage by their screw threads with the shaft I. The
plate of the traveller L, which is nearer the swaging machine, extends higher up
than the other plate and has an aperture near its upper end. The openings i are of
a diameter greater than that of the shaft I, so as to allow the sliding of the
traveller thereon, when the jaws m of the clamp M are in the position shown in
Figure 4.
P is a rod or arbor to support the tube Q. R is a loosely fitting sleeve upon the
arbor and ta metallic washer between said sleeve and the plate of the traveller.
The arbor P has a transverse groove near its end, as seen in Figure 3, and a pin u,
passing through a transverse hole in the bent end g of the bar K prevents the arbor
from turning. Braces S extend from the standard C to the face of the swaging
machine and are bolted to give stability to the structure.
The operation of this device is as follows. The tube Q the sleeve R and the
washer t are placed upon the arbor P, as shown in Figures 2 and 3.
The arbor P is locked in position by the pin in the slotted end g of the bar K.
The opposite end of the arbor and the end of the tube are passed between the dies a
of the swaging machine. The traveller L is brought in position to abut the
washer t and to bring the end of the sleeve R against the outer end of the tube Q.
The jaws of the clamp M are then shut to engage with the shaft I.
Now, by the revolution of the wheel E, the gearing G H rotates the shaft I, as
indicated by the curved arrow in Figure 2, and the traveller L, by its clamp con-
nection M with the shaft I, moves toward the swaging machine and by its forward
plate pushes the tube Q between and through the dies a. The guide rod J confines t
the movement of the traveller to a vertical plane. The dies a hammer down the
tube upon the arbor and reduce the thickness of the stock. The continual_but
gradual rotation of the shaft I forces off the hammered portion of the tube Q from
the arbor P and said tube as reduced, gradually passes out through the central
opening of the swaging machine, until the tube has been entirely reduced and
stripped from the arbor.

page_text: by removing the dies a and substituting other dies having a less calibre, the
tube Q may be again hammered down upon an arbor of less diameter and thus the
operation is repeated until the desired result is accomplished.
To reverse the movement of the traveller, the jaws of the clamp M are opened
by moving the handle N in a direction opposite to that indicated by the arrow in
Figure 4, whereupon the jaws are wholly disengaged from the shaft I and the
traveller L is pushed back toward the standard C by hand.
The adjustment of the bar K upon the top plate of the standard C allows a
sufficient movement to properly support by it the arbor P.
The action of the hammer dies gives to a gold-plated tube a much smoother and
better finish than is imparted by a draw-plate. The gold is compacted by the
blows and the product is superior to drawn tubing. The blows are so numerous
and rapid and the advance of the tube to the dies is so slow that every portion of
the surface is well hammered and retains its symmetrical appearance.
The portion of the tube which is in snug contact with the arbor is only that part,
which lies between the dies and a little beyond. The part of the tube which has
not reached the dies is loose upon the arbor. The part which has been subjected
to the dies passes off of the arbor at a short distance beyond them, as appears in
Figure 2.
Only a moderate degree of force is necessary to overcome the frictional engage
ment of the tube upon the arbor along this short distance and that power is applied to
the thicker butt end of the tube. The force or pressure to accomplish this stripping
action is that of a screw applied with great leverage and the resistance to be over-
come is limited to a short space. I am able thus to reduce and deliver greater
lengths or sections of tube than by the methods commonly used. I do not wish to
confine myself to the use of the particular swaging machine above described. Any
reducing machine having hammer dies may be used in this process. Neither do I
confine myself to the particular device specified to feed the tube to the reducing
dies. I have illustrated my improved process by the best means known to me,
but it is obvious that other feeding devices are also applicable to the process.
The end of the arbor P which passes through the opening of the dies should be
hardened, so as to endure the hammering action of the dies, but the remaining part
of the arbor does not need to be specially hardened. In this respect, also my
invention has an advantage over the common method, for it has hitherto been
necessary to have the arbor hardened throughout its entire length to resist the
action of the draw-plate, and this hardening must be uniform in order that it may
everywhere endure the pressure equally.
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 tube reducing mechanism herein-described, consisting of a
swaging machine having hammer dies adapted to reduce a tube, an arbor extending
through the aperture of the said dies, means for supporting the said arbor and a
feeding device, arranged to advance a tube along the said arbor to and between
said dies and off the arbor beyond the dies, when the said tube has been reduced,
substantially as specified.
Second. In combination with a tube-reducing machine having a central aperture
and swaging dies, an arbor extending through the said aperture and adapted to
support the tube which is to be reduced, a traveller suitably supported and movable
on the said arbor and placed to abut the rear end of the tube, a screw-threaded
shaft with means for rotating the said shaft and a nut or clamp connected with the
traveller and capable of engaging with or disengaging from the said screw-threaded
shaft, substantially as specified.
Third. The improved process of reducing tubes herein described consisting in
supporting a tube upon an arbor and moving the said tube along the said arbor to

page_text: the hammer dies of a reducing machine and off the said arbor as the reduction of
the tube is accomplished, substantially as specified.
Dated this 13th day of April 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.