IMPROVEMENTS IN THE MANUFACTURE OF CASED COVERED OR COATED TUBES
Year: 1884

page_text: I JAMES HUDSON of Tennant Street Birmingham in the County of Warwick
Tubo Manufacturer do hereby declare the nature of my said Invention for
IMPROVEMENTS IN THE MANUFACTURE OF CASED COVERED OR COATED TUBES
to be as follows:-
Hitherto tubes of this kind have usually been made either (1) by soldering the.
edges of the outer case or covering together and afterwards drawing it upon the
tube to be covered through suitable dies or (2) by turning the edges into the open
joint of the tube to be covered and locking it with another piece of metal or (3) by
forming a groove (i.e. by cutting or removing a part of the substance of the metal
thereby weakening the tube) in the tube to be covered and so fol·ling and locking
the metal which forms the outer case or covering that when it is drawn through
suitable dies the joint or folded part of the casing is forced into the said groove.
But in method N° 2 above described it is found in practice that a regular and good
joint cannot be produced by reason of the springing open of the tube after passing
the dies and much waste of material often occurs whilst in both of the methods
(2 & 3) it has been found in practice that a perfect lock joint is not obtainable.
By my improved method a good sound joint is produced and the loss from waste is
reduced to a minimum. I first provide a strip of iron or base metal which by
drawing through suitable dies I form into a tube having an open joint and on the
opposite side to this open joint is simultaneously formed a deep recess or indentation
extending below the line of the inner side of the tube, this recess or indentation is
by preference nearly V shaped. I next prepare by drawing through suitable or
chilled dies the strip of brass or other metal which is to form the casing or cover
with its two edges turned inwards as is now commonly the practice in the
manufacture of stair rods as referred to in Westons Specification N° 3315-1869,
this covering is then passed over the first mentioned tube of iron or base metal, the
tubes are then drawn together through suitable or chilled dies and may be reduced
in size to any desired degree. The effect of this last mentioned process is to close
the V shaped groove upon the inward turned edges of the outer casing and so
securely hold them therein. Inasmuch as the tendency of the V to spring open is
reduced to a minimum a much more perfect joint can by means of my Invention
be obtained than by either of the processes before referred to.
Dated this 12th day of January 1884

page_text: I JAMES HUDSON of Tennant Street Birmingham in the County of Warwick
Tube Manufacturer do hereby declare the nature of my said Invention for
IMPROVEMENTS IN THE MANUFACTURE OF CASED COVERED OR COATED TUBES
and in what. manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
Hitherto tubes of this kind have usually been made either (1) by soldering the
edges of the outer case or covering together and afterwards drawing it upon the
tube to be covered through suitable dies or (2) by turning the edges into the open
joint of the tube to be covered and locking it with another piece of metal, or (3) by
forming a groove (i.e. by cutting or removing a part of the substance of the metal
thereby weakening the tube) in the tube to be covered and so folding and locking
the metal which forms the outer case or covering that when it is drawn through
suitable dies the joint or folded part of the casing is forced into the said groove.
But in method N° 2 above described it is found in practice that a regular and good
joint cannot be produced by reason of the springing open of the tube after passing
the dies and much waste of material often occurs whilst in both of the methods
(2 and 3) it has been found in practice that a perfect lock joint is not obtainable.―
By my improved method a good sound joint is produced and the loss from waste is
reduced to a minimum. I first provide a strip of iron or base metal which by
drawing through suitable dies I form into a tube having an open joint and on the
opposite side to this open joint is simultaneously formed a deep recess or indentation
extending below the line of the inner side of the tube, this recess or indentation is
by preference nearly V shaped, I next prepare by drawing through suitable or
chilled dies the strip of brass or other metal which is to form the casing or cover
with its two edges turned inwards as is now commonly the practice in the
manufacture of stair rods as referred to in Westons Specification N° 3315-1869
this covering is then passed over the first mentioned tube of iron or base metal,
the tubes are then drawn together through suitable or chilled dies and may be
reduced in size to any desired degree. The effect of this last mentioned process is
to close the V shaped groove upon the inward turned edges of the outer casing
and so securely hold them therein.-Inasmuch as the tendency of the V to spring
open is reduced to a minimum a much more perfect joint can by means of my
Invention be obtained than by either of the processes before referred to. It will be
understood that in some cases and more particularly in the construction of larger
sized tubes it is sometimes desirable to form the iron or base metal tube by means
of suitable rolls.-That my Invention may be better understood I have annexed a
Drawing thereof which I will now proceed to describe. Fig. 1 is a transverse
section of the iron or base metal inner tube a in its first stage of bending, the open
joint being at a¹ and the recess or indentation being at a this being often not
made to its full depth by the first die or set of rolls through which it passes.
Fig. 2 is a partial elevation of the foregoing tube. Fig. 3 is a transverse section of
the iron or base metal tube a after it has passed through the die dies or rolls which
bring the edges together at the open joint a' and which give the proper depth to
the groove recess or indentation a³. It will be observed that the inner part of
this recess is "below" that is more nearly approaches the centre of the tube than
the general surface of the inside of the tube. Fig. 4 is a partial elevation of the
tube in the same stage of manufacture as Fig. 3. Fig. 5 is a transverse section
through the outer tube or casing b of brass or some other fine metal. This is
formed as is the inner tube a from a strip of metal by drawing through a die or
dies or passing through rolls, the edges b¹ bare it will be seen bent up so as to fit

page_text: into the recess a³ in the inner tube. Fig. 6 is a transverse section through the
two tubes a and b when the outer tube or casing b has been placed on the inner
one a but before the final stage of manufacture. It will be seen that the edges b¹ bl
fit into the groove or recess a². Fig. 7 is transverse section through the finished
cased tube which now has had its correct shape given to it and has had its size reduced
if desired, it will be seen that the sides of the V shaped groove a' are now forcibly
compressed together and they grip and hold perfectly fast the inward bent edges of
the outer casing. Fig. 8 is a partial longitudinal section through the finished cased
tube. The same letters of reference indicate the same parts in each of the Figs.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is
The approximately V shaped recess indentation or groove in the inner or base
metal part of a "cased tube" opposite or nearly so to the open joint the placing the
previously bent edges of the outer casing properly in this recess and the closing of
the sides of the groove or recess by passing the tube. through dies rolls or other
suitable tools thereby gripping the edges of the casing firmly and making a good
sound joint.
Dated this Twenty fourth day of April 1884.
0 Witness:
CHA³. JOHNSTONE,
Clerk to T. Emery Davies,
Solicitor,
Birmingham.
JAMES HUDSON.