Improvements in Metal Tubing and Methods of Making same.
Year: 1897

page_text: Date of Application, 12th July, 1897
Complete Specification Left, 10th May, 1898-Accepted, 11th June, 1898
PROVISIONAL SPECIFICATION.
Improvements in Metal Tubing and Methods of Making same.
JOHN HENRY TAYLOR and EDWARD CHARLES WASDELL, of 83, Lombard Street,
Birmingham, Tube Makers, do hereby declare the nature of this invention to be
as follows:-
By our invention we make metal tubing with a lap joint of a construction
superior to that generally in use. We make the tube out of strip metal & bend
it into tubular form by the usual rolling processes, but in course of these processes
we make the edges of the strips into a special and novel form as follows:-
We bend one edge of the strip into two folds or bends, the first bend turning
inwards or towards the centre of the tube & the next bend turning backwards
from this direction thus these two bends together with the adjoining portion of the
periphery of the tube form an exact representation of the letter Z;B the
other edge of the strip is brought round by the rolling processes above mentioned
till it fits into the lower angle of this Z; a bar is then put through the tube and
the tube passed through rolls or dies of such form that the Z shaped folds are
squeezed altogether & hold tight upon the other edge of the strip which has been
brought between them; this makes a very superior form of lap joint and
in the subsequent process of brazing, the joint cannot possibly come apart as is
frequently the case with the common form of lap joint tube.
Before bringing the one edge of the strip round into the angle of the Z as before
described, this edge may be slightly depressed towards the centre of the
tube in such a manner that, when the above described squeezing has been done,
the outer side of the Z shaped edge of the tube is flush with the other side of the
tube and the outside of the tube is truly circular.
We sometimes make a modified form of this tube in which both edges of the
tube have the Z like shape and after these edges are brought towards
each other, a very narrow strip of metal is inserted for the whole length of the
tube in the lower angles of the two Zs; this strip is secured by squeezing down as
before described and the tube brazed as usual.
Dated this 10th day of July 1897.

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:.
By our invention we make metal tubing with a lap joint of a construction
superior to that generally in use. We make the tube out of strip metal and bend
it into tubular form by the usual rolling processes, but in course of these processes
we make the edges of the strips into a special and novel form as follows:-
We bend one edge of the strip into two folds or bends, the first bend turning
inwards or towards the centre of the tube and the next bend turning backwards
from this direction; thus these two bends together with the adjoining portion of the
periphery of the tube form an exact representation of the letter Z, see Fig. 1; the
other edge of the strip is brought round by the rolling processes above mentioned
till it fits into the lower angle of this Z; a bar is then put through the tube and
the tube passed through rolls or dies of such form that the Z shaped folds are
squeezed altogether and hold tight upon the other edge of the strip which has been
brought between them, see Fig. 2; this makes a very superior form of lap joint and
if the tube is subsequently brazed, the joint cannot possibly come apart during
brazing as is frequently the case with the common form of lap joint tube.
Before bringing the one edge of the strip round into the angle of the Z as before
described, this edge may be slightly depressed, see Fig. 3, towards the centre of the
tube in such a manner that, when the above described squeezing has been done,
the outer side of the Z shaped edge of the tube is flush with the other side of the
tube and the outside of the tube is truly circular.
We sometimes make a modified form of this tube in which both edges of the
tube have the Z like shape, see Fig. 4, and after these edges are brought towards
each other, a very narrow strip of metal as shown is inserted for the whole length
of the tube in the lower angles of the two Zs; this strip is secured by squeezing
down as before described and the tube afterwards brazed if required.
We sometimes make a further modified form of this tube in which both edges
of the tube having the Z like shape (see Fig. 5) but one of the lower folds of
the Zs is longer than the other and projects into the other as shown. No narrow
strip of metal as in Fig. 4 is used in this case.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
-
(1) A metal tube with a lap joint formed by bending one edge of the strip of
metal to the form of a capital Z and fitting the other edge of the metal in the lower
fold of the Z and then squeezing the folds together substantially as hereinbefore
described.
(2) A similar tube, but with one edge slightly depressed so that the outside of
the tube comes truly circular substantially as hereinbefore described.
(3) A modified form of this tube in which both edges of the tube have the Z
like shape and a narrow strip of metal is inserted in the lower angles of the two
Zs substantially as herein before described.
(4) A further modification of this tube in which both edges of the tube have
the Z like shape, but the bottom fold of one of the Zs is made longer than the
other, and projects into the other substantially as hereinbefore described.
Dated this 9th day of May 1898.
JOHN HENRY TAYLOR.
EDWARD CHARLES WASDELL.