Improvements in the manufacture of Copper and other Metallic Tubes and in Apparatus Employed in the said Manufacture.
Year: 1887

page_text: Date of Application, 7th Jan., 1887
Complete Left, 1st Oct., 1887
Complete Accepted, 4th Nov., 1887
Improvements in the manufacture of Copper and other Metallic
Tubes and in Apparatus Employed in the said Manufacture.
I THOMAS BUDWORTH SHARP of French Walls Smethwick in the County of
Stafford Mechanical Engineer do hereby declare the nature of this Invention to be as
follows:-
In the specification of Letters Patent granted to me dated 30th day of January
1883 No. 491 I have described represented and claimed among other things a method
of drawing tubes of copper and alloys of copper by the employment of a draw plate
and a plug the relation between the size of the hole in the draw plate and the size and
shape of the plug being such that in drawing a tube the plug stations itself in the
eye" of the draw plate and the drawing of the tube is effected between the hole in
the draw plate and the shoulder of the plug.
"
32
It sometimes happens that a tube of copper or other metal or alloy is required
cylindrical without but slightly conical within or of different internal diameters at
different parts. In manufacturing such tubes I modify the patented invention referred
to in the following manner. I form on the front of the plug, that is, on the part of
the plug over which the tube passes after it has been drawn a stem or rod of a slightly
tapering or conical figure and I make this tapering or conical stem occupy the "eye"
of a second draw plate parallel to the first. The diameter of the hole in the second
draw plate is equal to the external diameter of the tube to be made. The second draw
plate is fitted with appliances by which it can be readily made to approach to and
recede from the first draw plate. As the second draw plate approaches the first
portions of the tapering or conical stem of the plug of progressively increasing
diameter occupy the eye of the second draw plate and conversely as the second draw
plate recedes from the first portions of the said tapering or conical stem of pro-
gressively diminishing diameter occupy the eye of the second draw plate. As the
thickness of the metal of the tube is determined by the part of the tapering or conical
stem which occupies the "eye" of the second draw plate (the external diameter of the
tube determined by the hole in the draw plate being fixed) it follows that by stationing
the second draw plate at a greater or less distance from the first the thickness of the
CD 31

page_text: metal of the tube produced may be increased or diminished. Similarly if the second
draw plate is made slowly to approach or recede from the first during the drawing
process the thickness of the metal of the tube will be gradually diminished or
increased and the tube produced while being cylindrical without will be conical
within.
By making the second draw plate stationary the tube produced will be of uniform
thickness of metal by changing the position of the second draw plate relative to the
first the thickness of metal of the tube may be changed and thus a tube tapering
inside and of uniform diameter outside or of different internal diameters at different
parts may be made.
Instead of moving the second draw plate the first may be made movable or both
draw plates may be made movable.
In drawing tubes by the use of the detached plug described in the specification of
the patent referred to there is no necessary limit to the length of the tube to be made
as there is where mandrils are employed.
When the tube made is of considerable diameter it is necessary to preserve it.
straight as in bending it the tube flattens or becomes nearly elliptical in cross section.
But tubes of small diameter may be coiled on a reel or drum and uncoiled therefrom
without injury to the tube and in making tubes of small diameter by the use of the
loose plug referred to I use a reel or drum by the rotation of which the drawing of
the tube is effected and the tube produced coiled on the said drum. The tube in
successive drawings may be uncoiled from one reel or drum and the drawing of the
tube effected by coiling it on another.
Datod this Seventh day of January 1887

page_text: Improvements in the Manufacture of Copper and other Metallic
Tubes and in Apparatus Employed in the said Manufacture.
I THOMAS BUDWORTH SHARP of French Walls Smethwick in the County of
Stafford Mechanical Engineer do hereby declare the nature of my Invention and in
what manner the saine is to be performed to be particularly described and ascer-
tained in and by the following statement:-
In the specification of Letters Patent granted to me dated 30th day of January 1883,
No. 491, I have described, represented and claimed among other things, a method of
drawing tubes of copper and alloys of copper by the employment of a draw plate
and a plug the relation between the size of the hole in the draw plate and the size
and shape of the plug being such that in drawing a tube the plug stations itself in the
eye" of the draw plate and the drawing of the tube is effected between the hole in
the draw plate and the shoulder of the plug.
<
It sometimes happens that a tube of copper or other metal or alloy is required
cylindrical without but slightly conical within, or of different internal diameters at
different parts. In manufacturing such tubes I modify the patented invention
referred to in the following manner. I form on the front of the plug that is on the
part of the plug over. which the tube passes after it has been drawn, a stem or rod
of a slightly tapering or conical figure and I make this tapering or conical stem
occupy the "eye" of a second draw plate parallel to the first. The diameter of the
hole in the second draw plate is equal to the external diameter of the tube to be made.
The second draw plate is fitted with appliances by which it can be readily made to
approach to and recede from the first draw plate. As the second draw plate approaches
the first, portions of the tapering or conical stem of the plug of progressively
increasing diameter occupy the eye of the second draw plate and conversely as the
second draw plate recedes from the first, portions of the said tapering or conical stem
of progressively diminishing diameter occupy the eye of the second draw plate. As
the thickness of the metal of the tube is determined by the part of the tapering or
conical stem which occupies the " eye of the second draw plate (the external
diameter of the tube deterinined by the hole in the draw plate being fixed) it follows
that by stationing the second draw plate at a greater or less distance from the first
the thickness of the metal of the tube produced may be made greater or less. Similarly
if the second draw plate is made slowly to approach to or recede from the first during
the drawing process the thickness of the metal of the tube will be gradually diminished
or increased and the tube produced while being cylindrical without will be conical
within.
By making the second draw plate stationary the tube produced will be of uniform
thickness of metal; by changing the position of the second draw plate relative to the
first the thickness of metal of the tube may be changed and thus a tube tapering
inside and of uniform diameter outside or of different internal diameters at different

page_text: parts may be made. Instead of moving the second draw plate the first may be made
movable or both draw plates may be made movable.
Figure 1 of the accompanying Drawing represents in section and Figure 2 in plan
the two draw plates brought into contact; Figures 3 and 4 represent the same views
as Figures 1 and 2 with the two draw plates separated a short distance apart and
Figures 5 and 6 represent the two draw plates separated to a greater distance apart
than is represented in Figures 3 and 4. When the two draw plates are in close
contact as represented in Figures 1 and 2, a tube is produced of uniform thickness of
metal. When the two draw plates are stationed as represented in Figures 3 and 4 a
tube is produced of uniform thickness of metal, the thickness of the metal in this
case being greater than that of the tube Figures 1 and 2. When the two draw plates
are stationed as represented in Figures 5 and 6 a tube is produced of uniform
thickness of metal the thickness of the metal being greater, than that of the tube
Figures 3 and 4.
The same letters of reference indicate the same parts in the several Figures of the
drawing.
a is the first draw plate and b the second draw plate parallel to the first. The said
draw plates a and b are made of hardened and tempered steel and are fixed in the
metal rings or holders a², 62 preferably by shrinking or contracting the said holders
upon the said draw plates but I do not limit myself to any particular arrangement for
building up the draw plates. The opposed faces of the said holders a², 62 are furnished
with broad inclines c, c engaged together, the said inclines, resembling large clutch
teeth and are for the purpose hereinafter described. The holes in the two draw
plates a and b are of different diameters, the hole in the second draw plate 6 being of
somewhat less diameter than that in the first draw plate a and the external diameter
of the tube to be drawn is determined by the diameter of the hole in the second draw
plate is the loose plug in the tube to be drawn the shoulder of the said plug
stationing itself during the drawing operation in the eye of the first draw plate a and
the drawing of the tube at the said first draw plate is effected mainly between the
hole in the draw plate and the shoulder of the pluge is the slightly tapering or
conical stem or rod on the front of the loose plug d which tapering or conical stem or
rod e occupies the eye of the second draw plate 6 and it is by causing different parts
of the said conical or tapering stem or rode to occupy the eye of the second draw
plate that the internal diameter and consequently the thickness of metal of the
finished tube is determined or a tube produced slightly conical within and cylindrical
without or having different diameters at different parts as hereinafter described. It will
be seen by reference to Figure 1 that when the two draw plates a and bare in
contact a portion of the cylindrical front end of the plug d is stationed in the eye of
the second draw plate b (although not necessarily so), no portion of the tapering
stem e being in action, hence a tube having the internal diameter of the cylindrical
portion of the plug is produced. When the two draw plates are separated and fixed
at the distance apart shown in Figures 3 and 4 the base of the tapering or conical
stem e or that part adjacent to the cylindrical part of the plug occupies the eye of the
draw plate band the annular space between the said part of the stem e and the hole
in the draw plate b is increased and the internal diameter of the tube being reduced
the thickness of the metal of the tube Figures 3 and 4 is greater than that of the tube
Figures 1 and 2. When the two draw plates are separated and fixed at the distance
apart represented in Figures 5 and 6, a part of the conical stem e of smaller diameter
occupies the eye of the second draw plate b and the annular space between the stem e
and the hole in the draw plate is correspondingly increased and the internal diameter
of the tube in this case is still further reduced than in the tube Figures 3 and 4 and
the thickness of the metal of the tube is consequently greater as represented in the
Drawing. In each case the external diameter of the tube drawn is the same.
direction in which the drawing takes place is indicated by the arrows. If the two
draw plates be made to slowly approach one another during the drawing operation the
thickness of the metal of the tube will be gradually diminished and if the two
draw plates are slowly separated the thickness of the metal of the tube gradually
The

page_text: becomes greater and greater, the tube being cylindrical without and conical within.
In the same manner a tube of different internal diameters at different parts may be
made. Or a tube of the kind represented in section in Figure 7 may be made by the
use of the two draw plates a and b and the loose plug d, e. The tube Figure 7 has
thick ends fand 7.and the tube tapers internally between the said ends. In making this
tube one of the thick ends f is first made by drawing it through the separated draw
plates as in Figures 5 and 6. After the thick end has been made the two draw
plates are slowly made to approach each other until the internal tapering part of
the tube has been produced. The two draw plates are then rapidly separated and
fixed at the distance apart first described for the formation of the other thick end g
of the tube. By reversing the motion described of the draw plates the internal
tapering of the tube Figure 7 may be reversed.
The separation and bringing together of the two draw plates are effected by the
action of the inclined faces of the holders a², 2 carrying the said draw plates. On
the said holders are pegs or handles f², for moving one or other or both of the draw
plates. By rotating the holder 6 of the second draw plate b so as to cause the bases
of its inclines c, c to travel towards the bases of the inclines c, c on the holder a² of the
first draw plate a the latter is separated from the draw plate 6 to the required extent
as seen in Figures 3, 4, 5 and 6; and by turning the holder a² of the first draw
plate a in a direction contrary to that in which the second draw plate was turned the
said first draw plate is made to approach the second draw plate.
I do not however limit myself to the arrangement described and represented for
causing the two draw plates to approach to or recede from one another as various
mechanical arrangements may be employed for that purpose which I do not consider
it necessary either to describe or represent.
Having now particularly described and ascertained the nature of my invention and'
the manner in which the same is to be performed I declare that I claim as my
invention ;-
First The improvements in the manufacture of copper and other metallic tubes
hereinbefore described and illustrated in the accompanying Drawing, that is to say,
making metallic tubes having a uniform external diameter and a varying or conical
or tapering internal diameter or having different internal diameters at different parts
by the process or processes substantially as herein before described and illustrated.
Secondly-Manufacturing copper and other metallic tubes by the use of two
parallel draw plates capable of being made to approach to or recede from one another,
the first draw plate being used in combination with a loose plug the acting part of
which stations itself in the eye of the said first draw plate during the drawing
operation the said loose plug having at its front a slightly tapering or conical stem or
rod different parts of which stem or rod can be made to occupy the eye of the said
second draw plate so that by stationing the second draw plate at a greater or less
distance from the first the thickness of the metal of the tube produced may be made
greater or less through its whole length or have different internal diameters at
different parts or by making the second draw plate slowly to approach to or recede
from the first during the drawing process a tube cylindrical without and conical
within through the whole or part of its length is produced substantially as herein before
described and illustrated in the accompanying Drawing.
Dated this Thirtieth day of September 1887
THOMAS BUDWORTH SHARP.