Improvements in Machinery or Apparatus Employed in the Manufacture of Seamless Drawn Metal Tubes.
Year: 1897

page_text: Date of Application, 4th Dec., 1897-Accepted, 22nd Jan., 1898
COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus Employed in the
Manufacture of Seamless Drawn Metal Tubes.
I, ELLWOOD IVINS, of Oak Lane, in the City of Philadelphia, State of
Pennsylvania, United States of America, Tube Manufacturer, 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 the class of tube drawing machines in which the tube
as it is drawn through the die plate is compressed upon a travelling core, or
mandrel, the object of my Invention being to provide means whereby the tube
can be readily removed from the mandrel when the drawing operation has been
completed.
This object I attain in the manner hereinafter described reference being had
to the accompanying drawing, in which Figure 1 is a diagranmatic view of
sufficient of a draw-bench to explain my Invention, the drawing of the tube
being illustrated in progress. Figure 2.is a similar view shewing the tube being
removed from the core or mandrel; Figure is an end view of the roller head
forming part of the machine; and Figure: 4 is a view illustrating a modification
of the invention. Part of the fixed structure of an ordinary draw-bench is repre-
sented at 1 in Figures 1 and 2, this structure providing a suitable bearing for the
draw-plate 2 through which the tube is to be drawn, the said tube, prior to
a core,
upon
or. mandrel, 3,
the drawing operation, being mounted
the
tube by
which
die plate with
is drawn through the
of a suitable connection with the draft chain 4. The effect of this operation is
to squeeze the tube down firmly upon the core, or mandrel, so that after the
drawing operation in order to effect the removal of the core, or mandrel it will
be necessary to expand the tube sufficiently to free the mandrel in some measure
from its hold.
means
According to my Invention I combine with the draw-head of the machine
means for so acting upon the tube, immediately after it issues from the draw-
plate, that by the time the drawing operation is completed, the drawn tube will
be expanded throughout its entire length and the core, or mandrel, can be
removed therefrom.
The means which I prefer to employ for effecting this expansion of the tube is
a series of rollers 5-5 and 6-6, the rollers 6-6 being arranged at right angles
to the rollers 5-5, and the rollers being so disposed that they will bear upon
the tube at four points which viewed transversely are equidistant (see Figure 3)
and will compress the said tube at those points sufficiently to cause it to bulge,
or spread, between the points of contact whereby the hold of the tube upon the
core, or mandrel, is so reduced that the said core, or mandrel, can, after the
passage of the tube through the rollers, be readily withdrawn by power suitably
applied to the end of the core or mandrel, opposite that to which power was
applied in drawing the tube.
In order to effect the ready withdrawal of the core or mandrel I use a supple-

page_text: mentary draft-chain 7 in front of the draw-head, this chain travelling in a
direction the reverse of the direction of movement of the chain 4. When the
tube and its core or mandrel, have been drawn through the die plate and rollers 5
and 6, a stripper plate 9 is applied to the draw-head as shewn in Figure 2 and
the rear end of the core, or mandrel, is passed through the opening in the said
plate 9 and connected by any suitable means to the rearwardly travelling drafk-
chain 7, the stripper plate being such as to act as a stop for the tube so that the
core, or mandrel will be withdrawn from the same and when so withdrawn, will
occupy a position in front of the draw-head where a new tube can be applied to it.
By this means any handling of the drawn tube, with its enclosed core, or
mandrel, is rendered unnecessary since there is no need to carry the tube from
the rear of the draw-head to the front thereof, or to turn the tube and its
enclosed core, or mandrel, end for end in order to permit of the withdrawal of
the core or mandrel, and therefore the whole operation can be very cheaply
and expeditiously-performed.
.
Instead of using two pairs of rollers arranged at right angles to each other as
a means of expanding the tube after drawing the same, I may use but a single
pair of rolls, or three rolls arranged to form a triangle, or I may employ more
than four rolls if desired, or in place of the rolls I may employ a solid head
having a central opening through which the tube is drawn, this opening being
so shaped as to impart pressure to the tube at two, or more, points on its periphery.
An instance of this construction is shewn in Figure 4.
draw
It will be evident also that my invention is applicable to that class of tube
drawing machines in which the drawing, or reduction, of the tube is effected by
means of grooved rollers instead of by a draw plate, hence under the term
plate" I include any means which may be employed for pressing the metal of the
tube down upon the core, or mandrel, in order to effect the reduction in the size,
or thickness, of the walls of the tube.
Having now described and particularly ascertained the nature of my Invention
and in what manner the same is to be performed I declare that what I
claim is:-
1st. The combination with a tube drawing bench of means for imparting
pressure to the tube at two, or more points on its periphery after it leaves the
draw plate or its equivalent whereby the tube is expanded sufficiently to allow
of the withdrawal of the internal core, or mandrel, as herein before explained.
2nd. The combination with a tube drawing bench, of a series of rollers disposed
so as to impart pressure to the drawn tube at two, or more, points on its periphery,
after it has left the draw plate or its equivalent.
3rd. The combination with a draw bench of means for imparting pressure to
the drawn tube, at two or more points on its periphery after it leaves the draw
plate or its equivalent and a reversely moving draft chain in front of the draw-
head whereby after the tube has left the draw plate or its equivalent and the
expansion device, the core, or mandrel, can be withdrawn from the tube and a
stripper plate for acting as a stop for the said tube whilst the core or mandrel
is being removed.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.