An Improved Flush Joint for Tubular Connections.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
An Improved Flush Joint for Tubular Connections.
I, ALFRED WILLIAM TURNER, Consulting Engineer, and International Patent
Agent, of Cobden Buildings, 67, Corporation Street, Birmingham, in the County
of Warwick (a communication from Frederick Christopher Avery, Machinist,
and Samuel Snell, Steel-Tube Manufacturer, both of Toledo, United States of
America), do hereby declare the nature of this invention to be as follows:-
The object of our invention is to produce a tubular flush joint, which shall be
simple, strong, and cheap in construction, for bicycle frames and for other struc-
tures where tubes are used jointed together by means of tube-fittings. By the
use of our invention a joint can be made without any forgings or stampings, by
the use of two tubular members that is to say a receiving-tube and an inserted
tube, but we wish it to be understood that our improved joint can be made two
or three ply, at or near the jointed connection, one of the tubes has a cut in it
to receive the other member; this tube with the kerfed groove, we call the receiving
member or receiving-tube; one end of the inserted tube is adapted to fit the
kerfed groove of receiving-member. When the tubular parts are in place the
inserted member is only passed partly through the receiving member, and abbuts
against a portion of the receiving member which supports the inserted member
in place, this portion of the receiving member which supports the end of the
inserted member, we call the "bridge portion." This bridge portion is made
by cutting the circular groove deep enough to allow the extreme end of the
inserted member to pass below the outer portion of the receiving member.
When the receiving member is of very thin gauge it is necessary to have the
entering end of the inserted member beveled in such a way that the angle of the
bevel will come tangent to the outside of the receiving member in order to allow
the largest amount of strength to the bridge portion. If the difference in the
size of the two tubes is not great the angle will be sharp and if there is a large
difference between the tubes the angle will be less acute.
When the two tubular parts are in place they have an inside and an outside
point of contact with each other which gives great support to the joint. When
this joint is brazed the brazing material will cling or lodge in the corners of the
joint, and with this inside and outside contact the joint will have four points of
contact where the brazing substance will hold, thus making a superior brazed
joint.
The inserted member may be clinched on the inside of the receiving member
if desirable to make the joint extra strong. When the receiving member is thick
the end of the inserted member need not be beveled on the inside.
From the description hereinbefore given it will be readily understood that we

page_text: are enabled to produce "a flush joint for the angular connection of tubing con-
sisting of a receiving member having a continuous circular kerfed seat cut entirely
through the cylindrical side at two opposite points, and having grooved out uncut
bridge pieces at intermediate points, in combination with the entering mem-
ber having its end inserted throughout its entire circumference into the kerfed
seat of the receiving member."
An improved Flush Joint for Tubular Connections.
I, ALFRED WILLIAM TURNER, Consulting Engineer, and International Patent
Agent, of Cobden Buildings, 67, Corporation Street, Birmingham, in the County
of Warwick (a communication from Frederick Christopher Avery, Machinist,
and Samuel Snell, Steel Tube Manufacturer, both of Toledo, United States of
America), 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:-
The object our invention is to produce a tubular flush joint which shall be
simple, strong, and cheap in construction and which shall be suitable for use in
the formation of bicycle frames and also in the formation of other structures
where tubes are used jointed together by means of tube fittings.
We will now proceed to describe with reference to the accompanying drawings
the manner in which our improved joints are constructed and used.
Figure 1, represents a side view of a piece of tube with the improved circular
groove or cut, the connecting member being shewn above the cut ready to enter.
Figure 2 represents a plan of the receiving tube of Figure 1.
Figure 3, represents a side view of a receiving tube grooved to receive the con-
necting member in an angular direction, the connecting member being shewn in
position for entering the angular groove.
Figure 4 represents a section through Figure 1 on the line A B with the con-
necting member inserted in its receiving groove.
Figure 5 represents a longitudinal section of Figure 2 on the line C–D).
Figure 6 represents a longitudinal section of Figure 3 with the connecting
member entered.
Figure 7 represents a view similar to Figure 1 excepting that the inserting
member is smaller.
.
Figure represents a transverse section of an improved joint carrying three
inserted connecting members.
Figure 9 represents a plan of Figure 8.
Figure 10, represents a vertical transverse section of Figure 7 on the line E F
with the connecting member entered.
In carrying out our invention we provide any ordinary tube as shewn at a
Figures 1 and 4 to form the receiving member, we pierce such receiving member
with a kerfed seat a cut entirely through the cylindrical side of tube a at two
opposite points, leaving a central plug-piece a² and two bridge pieces as by means
of which the plug piece a² is connected to the main tube a.
We next provide the inserted member b as shewn at Figure 1 in a position ready
to enter and as shewn introduced into the receiving member a at Figure 4; when

page_text: the two tubes a and b are connected as shewn at Figure 4 it will be seen that the
inserted member b is passed partly through the receiving member a and that it
abuts against the bridges a³ of the receiving member and is thereby supported
in position; the bridges as being produced by cutting a circular groove sufficiently
deep to permit of the inserted member b passing below the outer surface of the
receiving member.
The smaller inserted member ¹ as shewn at Figures 7 and 10, is connected to
the receiving tube as shewn at Figure 10 in the same manner that the tubes
are connected together as shewn at Figure 4, but the inward bevil 2 is of a less
acute angle than the inward bevil of Figure 4.
When the receiving member is of a very thin gauge the bridges a³ would not be
sunk below the outer surface of the receiving tube at the point e and the entering
end of the inserted member would be bevilled inwards in such a manner that the
angle of the bevil would be situated tangentially with the outside surface of the
receiving member a, thus permitting of the full thickness of the tube being
utilized to form the bridges a³.
If the difference in the sizes of the two tubes is not great the inward internal
angle of the entering tube will be acute and if there is a large difference between
the diameters of the receiving tube and the entering tube, the internal tangential
angle of the entering tube will be less acute, as may be perceived by inspection
of Figures 4 and 10.
It will be readily perceived on inspection of Figure 4 that when the two tubes
are connected there is an outside and an inside point of contact with each other,
which produces a joint with a maximum of surface support and when this im-
proved joint is brazed the brazing substance will cling or lodge in the angles of
the joints.
As an additional security the inserted member b may after introduction to the
receiving member a be clinched under the plug-piece a².
The inserted tubes and also the receiving tube can where desired be reinforced
at the joint, that is to say in relation to the inserted tubes a short piece can be
introduced into the inserting tube as shewn marked in dotted lines on the left
hand entering member of Figure 8; similar thimbles could of course be inserted
into the other two branches of Figure 8 and in a like manner the strengthening
thimble could be inserted into a single entering tube b of Figures 1 and 4.
To strengthen the receiving tubes thimbles would in some cases be inserted
beyond the circumferential outer surface f of inserted tube, but the receiving
tube may consist of two tubes, or three or more tubes within each other, such
compound tube being pierced through the whole of its layers to receive the enter-
ing member; the entering member may in a like manner be a compound tube
formed from several tubes within each other.
When forming the receiving tube with its plug piece g and bridges a¹ to receive
an inserting tube in an angular direction, the bridges a will be formed at right
angles with the centre or axis of the inserting tube, as shewn at Figures 3 and 6.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is-
1st. A flush joint for the angular connection of tubing, consisting of a receiving
member having a continuous circular kerfed seat cut entirely through the
cylindrical side of the tube at two opposite points, and having grooved but uncut
bridge-pieces at intermediate points; in combination with the tubular entering
member having its end inserted throughout its entire circumference into the
circular kerfed seat of the receiving member substantially as and for the purpose
described.
2nd. A flush joint for the angular connection of tubing, consisting of a receiv-
ing member having a continuous circular kerfed seat cut entirely through the

page_text: cylindrical side of the tube at two opposite points, and having uncut bridge-pieces
at intermediate points with acute angular grooves in them; in combination with
the tubular entering member having its end beviled upon the inner side and
inserted throughout its entire circumference into the circular kerfed seat of the
receiving member substantially as and for the purpose described.
Dated this Twelfth day of February 1898.
ALFRED WILLIAM TURNER,