Improvements in the Manufacture of Plain Cased Tubes, and in Tools to be used in the said Manufacture.
Year: 1897

page_text: Date of Application, 2nd July, 1897
Complete Specification Left, 23rd Mar., 1898-Accepted, 23rd Apr., 1898
Improvements in the Manufacture of Plain Cased Tubes, and in Tools
to be used in the said Manufacture.
We, TONKS LIMITED, of Moseley Street, Birmingham, in the County of Warwick.
Manufacturers, and WALTER REVILL, of No. 4, St. John's Road, Moseley,
Birmingham aforesaid, Tube Drawer, do hereby declare the nature of this
invention to be as follows:-
The said invention has reference to the manufacture of plain drawn cased tubes.
that is, tubes consisting of thin tubular outer casings say of brass drawn upon a
stronger steel or iron tubular foundation; and the said invention has for its object
not only to secure or fix the thin brass casing tube upon the foundation tube by,
the drawing operation, but at the same time to effect a reduction of the metal of
the casing tube and consequently an elongation of the said casing tube.
By the said invention the manufacture of plain cased tubes is economised and
their cylindrical figure perfected and the tubes so made are better fitted for the
subsequent polishing process than plain cased tubes of the ordinary manufacture.
We will describe the improved method of manufacture in conjunction with the
tools which we employ. We take a thin brass casing tube of the ordinary kind and we
take a foundation tube of the ordinary kind but of greater length than the said casing
tube and we draw or pull by hand the casing tube upon the foundation tube in the
position hereinafter described and we fix on the bed of the draw bench a com-
pound or double die for securing the casing tube upon the foundation tube and
for reducing the thickness of the metal of the casing tube and thereby iengthening
the said tube.
The said compound or double die consists of a front and back die plate arranged
face to face. The front die plate has a double or single conical draw hole of a size
suitable for reducing the thickness of the metal of the casing tube and at the same
time securing the said casing tube upon the foundation tube; and the back die
plate has a long guide hole in it of the exact diameter of the reduced casing tube
as it leaves the front reducing die plate. By the use of the said back die plate the
reduced tube is held very steadily during the drawing and reducing operation
upon the tube.
The thin casing tube having been pulled upon the longer foundation tube as
hereinbefore stated, leaving say, about one sixth of the foundation tube uncovered,
the extreme end of the covered part of the foundation tube is passed through the
compound die and the drawing operation effected in the ordinary way. no mandril
being used in the interior of the foundation tube.
By the operation of the front die plate of the compound die, the thin casing tube
is firmly secured upon the foundation tube and the metal of the casing tube is at
the same time reduced in thickness and elongated, the casing tube being so elongated
by the action of the reducing die plate that it is made to completely cover, the
foundation tube. As the reduced position of the tube leaves the reducing die it

page_text: enters and closely fills the back or guiding die plate whereby the tube is held very
steadily during the drawing operation.
Dated the 2nd day of Tuly 1907
Improvements in the Manufacture of Plain Cased Tubes, and in Tools
to be used in the said Manufacture.
We, TONKS LIMITED, of Moseley Street, Birmingham, in the County of Warwick,
Manufacturers, and WALTER REVILL, of No: 4, St. John's Road, Moseley,
Birmingham aforesaid, Tube Drawer, do hereby declare the nature of the sail
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:
'
A:
The said invention has reference to the manufacture of plain drawn cased tubes;
that is, tubes consisting of thin tubular outer casings, say, of brass, drawn upon a
stronger steel or iron tubular foundation; and the said invention has for its object
not only to secure or fix the thin brass casing tube upon the foundation tube by
the drawing operation but at the same time to effect a reduction of the metal of
the casing tube and consequently an elongation of the said casing tube.
By the said invention the manufacture of plain cased tubes is economized, and
their cylindrical figure perfected and the tubes so made are, better fitted for the
subsequent polishing process than plain cased tubes of the ordinary manufacture...;
We will describe the improved method of manufacture in conjunction with the
tools which we employ.
We take a thin brass casing tube of the ordinary kind and we take a
foundation tube of the ordinary kind but of greater length than the said casing
tube and we draw or pull by hand the casing tube upon the foundation tube,in the
position hereinafter described, and we fix on the bed of the draw-bench a com-
pound or double die for securing the casing tube upon the foundation tube and
for reducing the thickness of the metal of the casing tube and thereby lengthening
the said tube.
...
The said compound or double die consists of a front and back die plate arranged
face to face. The front die plate has a double or single conical draw hole of a size
suitable for reducing the thickness of the metal of the casing tube and at the same
time securing the said casing tube. upon the foundation tube; and the back' die
plate has a long guide hole in it of the exact diameter of the reduced casing tube
as it leaves the front reducing die plate. By the use of the said back die plate, the
reduced tube is held very steadily during the drawing and reducing, operation
upon the tube.
The thin casing tube having been pulled upon the. longer foundation tube, as
herein before stated, leaving, say about one sixth of the foundation tube uncovered,
the extreme end of the covered part of the foundation tube is passed through the
compound die and the drawing operation effected in the ordinary way, no¸ mandril
being used in the interior of the foundation tube.
By the operation of the front die plate of the compound die the thin casing tube
is firmly secured upon the foundation tube and the metal of the casing tube is at
the same time reduced in thickness and elongated, the casing tube being so elongated
by the action of the reducing die plate that it is made to completely cover, the
foundation tube. As the reduced portion of the tube leaves the reducing die it
711
J

page_text: enters and closely fills the back or guiding die plate whereby the tube is held
steadily during the drawing operation.
Figure 1 of the 'accompanying drawings represents in side elevation and
Figure 2 in plan, a portion of a draw-bench to which a compound or double die
constituting part of this invention is applied, a cased tube being drawn through the
compound or double die carried by the bed of the draw-bench.
Figure 3 represents the double die and cased tube in longitudinal section drawn
to a larger scale; Figure 4 represents in front elevation and section the front or
drawing die plate separately and Figure 5 represents in front elevation and section
the back or guiding die plate separately.
Figure 6 represents the thin casing tube a pulled by hand upon the longer
foundation tube b leaving the end portion c of the said foundation tube uncovered:
Figure 7 represents the finished cased tube after the thin casing tube a 'has been
fixed and drawn upon the whole of the foundation tube so as to completely cover the
latter by the operation of the compound or double die, and Figure 8 represents in
side elevation, end elevation and longitudinal section a portion of the finished cased
tube Figure 7 drawn to a larger scale.
The same letters of reference indicate the same parts in the several figures of
the drawings.
d is the front or drawing die plate having a double conical drawhole, that is,
each face of the die has conical opening meeting at the middle draw hole in
the die as represented. The draw hole in the die d is of a size suitable for reducing
the thickness of the metal of the casing tube and for securing the casing tube upon the
foundation tube; e is the back die plate having in it a cylindrical guide hole of
the exact diameter of the reduced casing tube as it leaves the front or drawing die
plate d. The compound or double die d, e is placed on the bed of the draw bench and
against the perforated stop plate f on the said bed as represented in Figures 1 and 2.
The thin casing tube a having been pulled by hand upon the longer foundation
tube bas represented in Figure 6, the extreme end a² of the covered part of the
foundation tube is passed through the compound die d, e and stop f on the draw
bench and the drawing operation effected in the ordinary way, the interior of the
foundation tube being without a mandril. As the compound tube is drawn through
the die plate & the thin casing tube a is fixed on the foundation tube b and the
metal of the casing tube a at the same time reduced and the tube
thereby elongated and made to completely cover the foundation tube b
as represented in Figure 7. As the reduced portion of the tube leaves
the front or reducing die d, it enters and closely fills the guiding hole
in the back plate e and the tube is thereby held very steadily during the drawing
operation as seen in Figure 3. By reference to the said Figure 3 it will also be seen
that the metal of the casing tube after it leaves the die plates d, e is reduced in
thickness and that the thicker portion of the casing tube at the front of the die d
is progressively thinned and elongated backwards for covering the end c of the
foundation tube.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that we claim as
the said invention:-
Manufacturing plain cased tubes by the process or combination of processes and
by the use of the tools herein before described and illustrated in the accompanying
drawings; that is to say, first pulling by hand the casing tube upon a longer
foundation tube so as to partly cover the said foundation tube and afterwards
drawing the compound tube through a compound or double die consisting of a
front drawing die plate and a back guiding die plate, the drawing operation through
the drawing die plate securing the casing tube upon the foundation tube and at the
same time reducing the thickness of the metal of the casing tube and thereby
lengthening the said casing tube and covering the whole of the foundation tube,
the reduced portion of the casing tube as it leaves the reducing or drawing die

page_text: entering and closely fitting the back or guiding die whereby the tube is held very
steadily during the drawing operation substantially as described and illustrated.
Dated the Nineteenth day of March 1898.
TONKS LIMITED,
W. H. TONKS,
P. TONKS,
Directors.
Secretary
W. H. TONKS, JUN.,