IMPROVE- MANUFACTURE OF METALLIC TUBULAR COILS USED IN DISTILLATION AND FOR OTHER PURPOSES AND IN MACHINERY OR APPARATUS USED IN THE SAID MANUFACTURE MENTS IN THE 12
Year: 1883

page_text: LETTERS PATENT to Thomas Budworth Sharp of French Walls Smethwick
in the County of Stafford Mechanical Engineer for an Invention of "IMPROVE-
MANUFACTURE OF METALLIC TUBULAR COILS USED IN
DISTILLATION AND FOR OTHER PURPOSES AND IN MACHINERY OR APPARATUS
USED IN THE SAID MANUFACTURE
MENTS IN THE
12
PROVISIONAL SPECIFICATION left by the said Thomas Budworth Sharp at
the Office of the Commissioners of Patents on the 15th November 1883.
THOMAS BUDWORTH SHARP of French Walls Smethwick in the County of
Stafford Mechanical Engineer " IMPROVEMENTS IN THE MANUFACTURE OF
IN DISTILLATION AND FOR OTHER PURPOSES
AND IN MACHINERY OR APPARATUS USED IN THE SAID MANUFACTURE
METALLIC TUBULAR COILS USED
"
The metallic tubular coils to which my invention principally relates are the coils
of copper and tin tubing used in distillatory operations; the coils of iron tubing
used for heating by steam and other like coils used for analogous purposes. The
said coils are of the same diameter throughout and are of a helical figure.
The said coils are ordinarily made from straight tubing. A piece of straight
tubing is filled with lead or rosin or sand to prevent its collapse while under
treatment and the filled tube is bent or coiled on a cylindrical drum or other
cylindrical body. After the tube has received the required belical figure the lead
or rosin is melted out or the sand poured out. Where a long coil is required two
or more coils made in the way described are joined by soldering or brazing. When
lead or rosin has been employed to fill the straight tube it is not possible by fusion
wholly to remove these substances and the unremoved portions of these substances
contaminate more or less the liquid condensed in the coil if the coil is used in
distillation.
I will describe my method of manufacturing the said coils in conjunction with
the machinery or apparatus I employ.
I take a piece of metallic tube of a length somewhat greater than that of the
coil to be made and of an internal diameter somewhat less than that of the coil to
be made. I take a cylindrical rod or mandril of a diameter slightly less than the

page_text: internal diameter of the tube to be operated upon and of a length somewhat
greater than the length of the tube to be operated upon. One end of this mandril
(which end I will call the rear end) is shaped so that it can readily be held by the
ordinary drawing apparatus the other end of the said mandril (which end I will
call the front end) is curved into the figure of about one fourth of one of the
convolutions of the coil to be made. On this curved fore end of the mandril I
make three or other number of spherical bulbs of slightly greater diameter than
that of the interior of the tube to be operated upon.
Or the said bulbs may be
dispensed with and the curved part of the mandril made of somewhat greater
diameter than the straight part,
The mandril is passed onto the tube by its rear end and a series of short tubular
packing pieces fitting the mandril loosely are passed onto the rear end of the
mandril. The said end of the mandril is then passed through the hole in the
drawback of the draw bench and the mandril is drawn through the tube. As
the curved end of the mandril is drawn into the tube it gives to the tube its own
curved figure the bulbs on the said curved end of the mandril slightly enlarging
the internal diameter of the coiled part of the tube and giving the interior of the
coil a smooth and polished surface. As the curved end of the mandril is drawn
through the whole length of the tube every part of the said tube is operated upon
in a similar manner and a helical coil produced. The tubular packing pieces
between the drawback and the rear end of the tube permit of the curved portion of
the mandril being drawn through the last portion of the rear end of the tube and
the waste at the ends of the coil is thus reduced to a minimum.
Although I prefer to make the curved end of the mandril of larger diameter
than the straight part or provide it with bulbs as described yet the curved end of
the mandril may be of the same or about the same diameter as the straight part
and unprovided with bulbs.
Although my invention is specially applicable to the manufacture of metallic
tubular coils of the kind described yet it may with slight modifications be applied
to the manufacture of metallic tubular coils of other kinds such for example as
coils having the figure of a spiral or an involute or other curve.
My invention is applicable to the manufacture of metallic tubular coils from
taper tubes as well as from tubes of the same diameter throughout.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Budworth Sharp in the Patent Office on the 18th March
1884.
THOMAS BUDWORTH SHARP of French Walls, Smethwick in the County of
Stafford, Mechanical Engineer "IMPROVEMENTS IN THE MANUFACTURE OF
METALLIC TUBULAR COILS USED IN DISTILLATION AND FOR OTHER PURPOSES AND
IN MACHINERY OR APPARATUS USED IN THE SAID MANUFACTURE
"
The metallic tubular coils to which my invention principally relates are the
coils of copper and tin tubing used in distillatory operations, the coils of iron
tubing used for heating by steam and other like coils used for analogous purposes.
The said coils are of the same diameter throughout and are of a helical figure.
The said coils are ordinarily made from straight tubing. A piece of straight
tubing is filled with lead or rosin or sand to prevent its collapse while under
treatment and the filled tube is bent or coiled on a cylindrical drum or other
cylindrical body. After the tube has received the required helical figure the lead
or rosin is melted out or the sand poured out. Where a long coil is required two
or more coils made in the way described are joined by soldering or brazing. When
lead or rosin has been employed to fill the straight tube it is not possible by fusion
wholly to remove these substances and the unremoved portions of these substances
contaminate, more or less, the liquid condensed in the coil, if the coil is used in
distillation.
I will describe my method of manufacturing the said coils in conjunction with
the machinery or apparatus I employ.
I take a piece of metallic tube of a length somewhat greater than that of the
coil to be made and of an internal diameter preferably somewhat less than that of
the coil to be made. I take a cylindrical rod or mandril of a diameter slightly less
than the internal diameter of the tube to be operated upon and of a length
somewhat greater than the length of the tube to be operated upon. One end of
this mandril (which end I will call the rear end) is shaped so that it can readily
be held by the ordinary drawing apparatus; the other end of the said mandril
(which end I will call the front end) is curved into the figure of about one fourth
of one of the convolutions of the coil to be made. On this curved fore end of the
mandril I make three or other number of spherical bulbs preferably of slightly
greater diameter than that of the interior of the tube to be operated upon. Or the
said bulbs may be dispensed with and the curved part of the mandril made of
somewhat greater diameter than the straight part.
The tube is passed onto the mandril and a series of short tubular packing pieces
fitting the mandril loosely are passed onto the rear end of the mandril. The said
end of the mandril is then passed through the hole in the draw-back of the draw-
bench and the mandril is drawn through the tube. As the curved end of the
mandril is drawn into the tube it gives to the tube its own curved figure, the bulbs
on the said curved end of the mandril (when the mandril bas bulbs) slightly
enlarging the internal diameter of the coiled part of the tube and giving the
interior of the coil a smooth and polished surface. As the curved end of the
mandril is drawn through the whole length of the tube every part of the said tube
is operated upon in a similar manner and a helical coil produced. The tubular
packing pieces between the drawback and the rear end of the tube permit of the
curved portion of the mandril being drawn through the last portion of the
rear end of the tube and the waste at the ends of the coil is thus reduced to a
'minimum.

page_text: Although I prefer to make the curved end of the mandril of larger diameter
than the straight part or provide it with bulbs as described yet the curved end of
the mandril may be of the same or about the same diameter as the straight part
and unprovided with bulbs
Although my invention is especially applicable to the manufacture of metallic
tubular coils of the kind described yet it may with slight modifications be applied
to the manufacture of metallic tubular coils of other kinds such for example as coils
having the figure of a spiral or an involute or other curve.
My invention is applicable to the manufacture of metallic tubular coils from
slightly taper tubes as well as from tubes of the same diameter throughout.
I will now proceed to describe with reference to the accompanying Drawings the
manner in which my invention is to be performed.
Figure 1 represents in longitudinal section and Figure 2 in plan, a helical coil
in course of manufacture according to my invention, the said Figures 1 and 2 also
illustrating the apparatus constituting part of my invention used in the said
manufacture
The same letters of reference indicate the same parts in both Figures.
a is a strong wooden plank or table upon which the rod or mandril, tube and
coil are supported; b is the fixed draw back of the draw-bench and c, c² is the
cylindrical rod or mandril, c being the straight part and c² the curved fore end.
The rear end of the part c of the rod or mandril is recessed at d so that it can be
attached to the draw bench wagon in the ordinary way. The curved fore end c*
of the rod or mandril is plain and bent into the figure of about one fourth of one
of the convolutions of the coil to be made, the said curved fore end c² being of
somewhat greater diameter than the straight part c; e is the tube to be made into
a coil and f are the short tubular packing pieces fitting the part c of the mandril
loosely, the rear packing piece of the series bearing against the draw-back b of the
draw-bench. It will be seen by an examination of the Drawing that the straight
part c of the rod or mandril fits the tube e loosely while the curved fore end c² of
greater diameter fits tightly the part of the tube upon which it is operating.
In manufacturing a coil according to my invention I proceed as follows:-
I place the rear straight part c of the rod or mandril in the front end of the
straight tube e (which tube has a length somewhat less than that of the rod or
mandril,) and pass it into the tube until that part of the mandril where the curved
fore end c³ sets in comes against the front end of the tube.
I then place upon
the rear end of the mandril a series of short packing pieces f. The rear end of the
mandril is then passed through the hole in the draw-back b and connected at d
with the drawing apparatus of the draw-bench and the mandril is drawn through
the tube, the tube being prevented from advancing on the mandril by the packing
pieces f taking a bearing against the draw-back b. As the curved fore end c³ of
the mandril c, c2 is drawn into the stationary tube e, the said curved end c³ gives
to the said tube its own curved figure and as the said curved end is drawn through
the whole length of the tube every part of the tube is operated upon in a similar
manner and a helical coil g thereby produced, the several convolutions of the coil
being delivered from the fore end of the mandril nearly parallel therewith and
making a coil the axis of which is at right angles to the mandril.
During the
making of the coil in the manner described, the coil travels with the shortened
tube by rolling upon the plank or table a. As the enlarged curved fore end c³ of
the mandril is drawn into the tube e it slightly enlarges the internal diameter of
the coiled part and gives to it a smooth and polished surface.
By using the packing pieces f between the rear end of the tube e and the draw-
back the curved fore end of the mandril can be drawn through the last
portion of the rear of the tube and the waste at the ends of the coil is thus reduced
to a minimum.
In making an involute coil according to my invention I modify the parts of the
apparatus in the manner represented in vertical section in Figure 3 and in hori-
zontal section (partly in edge view) in Figure 4.

page_text: The mandril c, c³, packing pieces f and draw-back b are the same as in the first
described arrangement, but I combine with the apparatus a wooden drum h upon
which the tube e, after it has been operated upon by the mandril, is coiled. The
said wooden drum h is provided with circular discs or side plates h³, h³ of
considerably larger diameter than the wooden drum h which discs are fixed to the
drum by the screw bolt and nut at i. The plank or table k upon which the
mandril C,
c and other parts rest, is situated edgeways and the circular discs h³, h³
of the drum & bear against the sides of the said plank as seen in Figure 4. The
first convolution of the involute coil is coiled upon the drum h by the action of the
curved fore end c³ of the mandril upon the tube e and the next and succeeding
convolutions are coiled upon one another being confined in the space between the
circular discs or sides h³, h³ of the drum h so as to produce a flat involute coil.
As the convolutions are coiled upon the drum and upon one another the drum and
parts carried by it advance by a rolling motion towards the draw back b the drum
rising from the table or blank k as the coiling operation proceeds as will be
understood by an examination of Figure 3. After the involute coil has been made
in the manner described it is drawn from the drum h by removing one of the side
plates or discs hs, h³ from the said drum.
The coil wound upon a drum of the kind represented in Figure 3 has a figure
sufficiently resembling an involute for general purposes but where it is desired that
the coil shall have the exact figure of an involute, I make the body of the drum of
the figure of an involute as represented in Figure 3A the distance from a toy being
equal to the diameter of the tube. In using this drum the inner end of the coil
is made to abut against the shoulder x, y.
In making a conical coil according to my invention I use a conical drum 7 as
represented in Figures 5 and 6, the said drum having removeable side plates 12, 13
fixed by the screw bolt m. As the tube e is coiled upon the drum by the action
of the curved fore end c² of the mandril, the said drum rolls along the inclined
plank or table a and in addition to its rolling motion has a motion at right angles
to the direction of the tube being coiled. That is, as the coiling on the drum
proceeds a lateral motion is given to the drum so as to bring a different part of
the drum into position to receive the next coil. The mandril c, c², packing pieces f
and draw back b are the same as corresponding parts in the arrangement Figures 1
and 2, excepting that the fore end c³ of the mandril has nearly the curvature of the
smaller end of the drum l.
By varying the shape of the drum the configuration of the coil may be varied.
The drum in cases where the coil cannot be removed from it by a sliding motion
is made in parts which parts can be separated for the purpose of liberating the coil
from the drum.
Figure 7 represents the curved fore end of the rod or mandril provided with
bulbs which is the form of mandril I employ when the internal diameter of the
coil is required to be considerably greater than that of the tube operated upon and
when it is necessary or desirable that the interior of the coil should be highly
polished. When however very thin tubing is operated upon the plain or unbulbed
mandril herein before described and represented should be used in preference to
the bulbed mandril Figure 7.
When a coil is produced in the manner described and represented with respect to
Figures 1 and 2 it has the figure of a compact helix the convolutions of which
touch or nearly touch each other. When it is wished to produce an elongated coil or
helix it may be done by taking the compact helix Figure 2 attaching one end to a
fixed support and drawing out the other end in the direction of the axis of the
coil. In this way the helix may be lengthened to such an extent where required
that the coil differs little from a straight tube. Or an elongated helix may be
produced directly from the straight tube by employing a mandril the terminal
or acting part of which has the curvature similar to that which it is desired to give
the tube.

page_text: .
I have described and represented the method of manufacture and the machinery
and apparatus which I commonly employ and which I find answer well in practice
yet I wish it to be understood that I do not limit myself to the machinery or
apparatus described and represented as any machinery or apparatus by which the
mandril may be drawn through the tube or the tube pushed off the curved end of
the mandril may be employed. In the case of small tubes of thin metal the
mandril may be drawn through the tube by hand. Or the mandril may be fixed
and the tube drawn or pushed off the mandril by the application of pressure in the
required direction on a plain part of the tube.
Having now described the nature of my invention and the manner in which
the same is to be performed I wish it to be understood that I do not limit
myself to the precise details herein described and illustrated as the same may
be varied without departing from the nature of my invention But I claim as my
invention;-
First The method hereinbefore described and illustrated in the accompanying
Drawings of manufacturing metallic tubular coils used in distillation and for other
purposes; that is to say, manufacturing the said coils from straight lengths of
tubing by the use of a rod or mandril the fore end of which has a curved figure
and is preferably of larger diameter than the straight part, or is of the same
diameter as the straight part and provided with bulbs, which curved end of
the rod or mandril being drawn into the stationary length of tubing bends or
fashions the said length of tubing into a coil in the manner substantially as
described and illustrated.
Secondly The construction and combination of the parts of machinery or
apparatus herein before described and illustrated in Figures 1, 2, and 7 of the
accompanying Drawings to be used in the making of metallic tubular coils of the
same diameter by the method of manufacture claimed in the first claim.
Thirdly The construction and combination of the parts of machinery or
apparatus herein before described and illustrated in Figures 3, 4 and 7 of the
accompanying Drawings to be used in the making of involute coils by the method
of manufacture claimed in the first claim.
Lastly-The construction and combination of the parts of machinery or apparatus
herein before described and illustrated in Figures 5, 6 and 7 of the accompanying
Drawings to be used in the making of conical or taper coils or spirals by the method
of manufacture claimed in the first claim.
In witness whereof I the said Thomas Budworth Sharp have hereunto set my
hand and seal this Eighth day of February in the year of our Lord one thousand
eight hundred and eighty four
THOMAS BUDWORTH SHARP (15)