Improvements in the Joints of Seamed Tubing and Tubular Articles;
Year: 1899

page_text: Date of Application, 14th Apr., 1899.
Complete Specification Left, 18th Nov., 1899-Accepted, 20th Jan., 1900
PROVISIONAL SPECIFICATION,
Improvements in the Joints of Seamed Tubing and Tubular Articles;
We, HARVEY DU CROS, Junior, of Metchley House, Edgbaston, in the City of
Birmingham, Gentleman, and CHARLES THOMAS BROCK SANGSTER, of 197, Bristol
Road, Birmingham aforesaid, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention has relation to joints for connecting or locking together the
meeting edges of seamed metallic tubing and tubular articles, such as front and
rear fork blades for cycles, cycle back stays and tubing for other parts of cycle
frames, said tubes being either parallel sided or tapered, and of a round, ellip-
tical, D or other cross section.
According to our invention a seamed tube is formed by taking a strip of sheet
metal, preferably steel, and providing the edges of the opposite sides with a
series of locking or infibulating projections, separated from each other by corres-
pondingly shaped recesses, with the series of projections along the one edge
coming immediately opposite the series of recesses of the other edge. The whole
of the projections or male parts are inclined or slightly canted out of the general
plane of the edge, somewhat like the set of a saw tooth, or in other words, each
projection is twisted to the same extent about its own axis as a centre, so that
on the two edges being brought together in the same horizontal plane, the
projections on each edge can be introduced laterally into the opposed corres-
ponding recesses on the opposite edge and on flattening down the projections or
restoring them to the plane of the edge, they form a perfect fit within the
recesses and a close seamed and interlocked joint is formed between the edges.
This joint may be reinforced by brazing or soldering and dressed by grinding
and polishing or by drawing through a die.
We propose that the projections and their corresponding recesses should be
made in the shape of a spear head, or lozenge or diamond shape, with the pro-
jections twisted about their major axes so as to all rake in the same direction,
and when so twisted the breadth of each projection (taken in plan) is rather
less than the recess with which it is to be infibulated but is made to completely
fill up the said recess on flattening.
Instead of the projections being of a spear head shape, they may be dovetail
or circular or elliptical or of any other figure so long as they have an enlarged
outer part or head connected to the body part of the strip by a neck or reduced
part, whereby the head or enlargement is prevented from being withdrawn
laterally from its corresponding recess after the flattening or straightening has
been performed.

page_text: Improvements in the Joints of Seamed Tubing and Tubular Articles.
We, HARVEY DU CROS, Junior, of Metchley House, Edgbaston, in the City of
Birmingham, Gentleman, and CHARLES THOMAS BROCK SANGSTER, of 197, Bristol
Road, Birmingham aforesaid, Engineer, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention has relation to joints for connecting or locking together the
meeting edges of seamed metallic tubing and tubular metallic articles, such as
front and rear fork blades for cycles, cycle back stays and tubing for other parts
of cycle frames, said tubes being either parallel sided or tapered, and of a round
elliptical, D or other cross section.
According to our invention a seamed tube is formed by taking a strip of sheet
metal, preferably steel, and providing the edges of the opposite sides with a
series of locking or infibulating projections, separated from each other by corres-
pondingly shaped recesses, with the series of projections along the one edge
coming immediately opposite the series of recesses of the other edge. The whole
of the projections or male parts are inclined or slightly canted out of the general
plane of the edge, somewhat like the set of a saw tooth, or in other words, each
projection is twisted to the same extent about its own axis as a centre, so that
the two edges being brought together in the same horizontal plane, the
projections on each edge can be introduced laterally into the opposed corres-
ponding recesses on the opposite edge and on flattening down the projections or
restoring them to the plane of the edge, they form a perfect fit within the
recesses and a close seamed and interlocked joint is formed between the edges.
This joint may be reinforced by brazing or soldering and dressed by grinding
and polishing or by drawing through a die.
In the accompanying drawings Figure 1 represents a plan of a piece of sheet
steel the edges of which are formed with alternating projections and recesses
adapted to be infibulated with one another to form a lock joint for a scamed
tube according to our invention.
Figure 2 is a cross section of Figure 1 upon the dotted line a.
Figure 3 is an edge view of the said strip Figure 1, showing how the teeth
or projections are inclined at an angle relative to the general plane of the edge
prior to being laterally introduced into their corresponding recesses.
Figure 4 is a sectional view showing the blank bent up into tubular form
but before the opposite edges thereof are connected together.
Figure 5 represents a plan of a piece of tube showing the completed joint and
Figure is a cross section thereof upon the dotted line r¹.
Figure 7 represents in plan and upon an enlarged scale, the joint as it appears
after the projections or teeth on the opposite edges have been introduced into
their corresponding recesses but before they are flattened, thus showing how the
normal width of the teeth is reduced by the twisting to admit them being intro-
duced laterally into the recesses.
Figure S is a plan view on the same scale as Figure 7 showing the edges in
the act of being infibulated into one another and exemplifying how the opposite
sets of twisted teeth ride over one another like inclined planes when being passed
laterally into position.
The several views are marked with like letter of reference to indicate corres-
ponding parts, a being the flat steel blank; b, c, the two sets of teeth or pro-

page_text: jections upon the opposite edges and d, e the corresponding opposite sets of
recesses, which alternate with the projections as previously described.
In the form of joint shown in the drawings, the projections b, c and their
corresponding recesses d, e, are made in the shape of a spear head, or of a
lozenge or diamond figure and we wish it to be observed that when the pro-
jections are twisted or skewed about their major axes so as to all rake in the same
direction, the breadth of each projection (taken in plan) is rather less than that
of the recess with which it is to be infibulated but is made to completely fill up
the said recess on flattening.
Instead of the projections being of a spear head shape, they may be dovetail
or circular or elliptical or of any other figure so long as they have an enlarged
outer part or head connected to the body part of the strip by a neck or reduced
part, whereby the head or enlargement is prevented from being withdrawn
laterally from its corresponding recess after the flattening or straightening has
been performed.
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:
-
First A joint for seamed tubing and tubular articles, formed by providing
the opposite edges of a length of metal, with a series of spear-head, diamond or
lozenge shaped projections alternating with a series of corresponding recesses,
the projections of each edge being infibulated or interlocked with the opposite
recesses of the other edge, substantially as described and set forth.
Secondly:- A joint for seamed tubing and tubular articles providing the
opposite edges of a length of metal with a series of headed projections alterna-
ting with a series of corresponding projections, which said projections are twisted
or skewed in the same direction, introduced laterally into the opposite correspond-
ing projections and then made to interlock therewith by flattening them, sub-
stantially as described and set forth.
D
1 1
121
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HARVEY DU CROS.
CHARLES THOMAS BROCK SANGSTER.
By Henry Skerrett,
emple Row, Birmingham, Agent for Applicants.