Improvements in or relating to Tubular Joints suitable for use in Cycle Frames.
Year: 1897

page_text: Date of Application, 27th Jan., 1897
Complete Specification Left, 27th Oct., 1897-Accepted, 27th Jan., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Tubular Joints suitable for use in
Cycle Frames.
I, JAMES RICHARD TRIGWELL, of 146, Brixton Hill, in the County of Surrey,
Cycle Manufacturer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to tubular joints applicable for various purposes, but
particularly suitable for use in the manufacture of cycle frames, and I will
describe it as so applied. Assuming that I have to joint the tube to the bottom lug
of the head of a bicycle frame I place the tube inside the branch of the lug, and
through the other end of the tube or through the hole in the lug I insert a
nut into the tube-the nut may be an easy fit in the tube or may be otherwise
held when it is desired to prevent it from turning or moving as for example
by a spring. I then place into the tube after the nut preferably three circular
and tapered segments centrally recessed and tapered to receive a tapered mandrel,
the end of which is screwed to fit the nut. This screw-thread is an exceedingly
fine one so that while serving as a purchase for the end of the mandrel, it may
also be employed as the means of feeding the mandrel and segments into the.
tube. Each segment may be slotted to receive a roller, and as the mandrel is
screwed in it forces out the segments, opening out the tube inside the lug and
slightly tapering both of them.
After this I employ a mandrel having a cone or ball race upon it with the
required number of balls, and inserting this into the joint and rotating the
mandrel I form any desired number of grooves, thus forcing the tube at those
parts into still more intimate contact with the lug and making an exceedingly.
tight joint.
Finally I may employ plain conical segments in conjunction with the mandrel
as before for the purpose of smoothing off and generally finishing the joint.
The joint as above described is a complete and efficient joint, but in the case
of frames for cycles, self-propelled vehicles and the like subject to considerable
strain and vibration I prefer to add a liner which may be done by placing inside
the joint a short length of tube of a suitable size and strength, and forcing it,
outwards against the interior of the joint by one or all of the operations previously.
described. The liner may be a piece of parallel tube, to which the necessary.
taper would be imparted in the operation of fixing it. Where the shape of the
lug is such as to prevent the entrance and withdrawal of the mandrel, and the
latter cannot be applied or worked from the other end of the tube, a hole may
be made in the lug to accommodate the mandrel; this hole may be afterwards
plugged up if desired in any convenient manner, or in some cases, it may be
left open and utilized for any purpose to which it may be applicable.
The mechanism employed in and the order of the above processes may be

page_text: varied without departing from the spirit of the invention, and the particular
tools or implements employed may be of any suitable construction, dimensions or
form. For example, the separate processes above described may be carried out
simultaneously or at a single application of the tools.
A joint thus made besides being in itself an efficient joint has the advantage
of dispensing with the brazing usually employed for frame joints for cycles, thus
getting rid of an important objection on account of the damage to the tubes from
the heat necessary in making such a joint, and the loss of time and liability to
damage due to making and cleaning it.
Instead of making grooves or in addition to grooves, I may use points which
force small portions of one member of the joint into the other member like a
number of centre-dabs. These points may be carried upon segmental and
operated pieces as before.
Dated this 27th day of January 1897
BOULT & WADE,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Tubular Joints suitable for use in
Cycle Frames.
I, JAMES RICHARD TRIGWELL, of 146, Brixton Hill, in the County of Surrey,
Cycle Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to tubular joints applicable for various purposes, but
particularly suitable for use in the manufacture of cycle frames, and I will
describe it as so applied.
The joints are made by expanding the tube inside a lug or socket by means of
special apparatus which will be presently described with the assistance of the accom-
panying drawings. The complete operation consists in first expanding the tube
inside the socket; second in forcing outwards portions of the tube into the
socket and third in fixing a supporting liner inside the tube, so that the latter
lies between the liner and the socket.
In the accompanying drawings,
Figure 1 is a section of the tube socket and instrument for carrying out the
first operation;
Figure 2 being a cross section upon the line 2-2 of Figure 1,
Figures 3 and 4 are views respectively similar to Figs. 1 and 2 and illustrate
the second operation and
Figures 5 and 6 are respectively similar views illustrating the third operation.
Like letters indicate like parts throughout the drawings.
Commencing first with Figures 1 and 2 A represents the lug which according
to the particular part of the frame where the joint is to be made will vary in
shape, but is here shown as the bottom lug of the head of the frame of an
ordinary safety bicycle.
or
B is the tube, the end of which is to be expanded inside the branch.
socket A¹ of the lug A, this branch being by preference tapered so that the outer
end of the branch at A2 is smaller in diameter than the inner end at A³. The
apparatus by which the various operations are carried out comprises a mandrel C
squared at its outer end C¹ or otherwise provided with means by which it may
be turned and screw-threaded at its inner end C², so as to engage with a nut I)

page_text: which may be a sufficiently tight fit in the tube B, or may in any convenient
manner be prevented from turning, as for example by means of a spring.
The mandrel C passes through a hole A provided for the purpose in the lug A.;
this hole may be afterwards filled up in the following manner, or it may be
left open and utilised for any purpose to which it may be applicable.
The hole A is threaded with a fine screw-thread and provided with one or
more nicks, recesses or projections and a soft metal plug preferably of copper
somewhat thicker than the wall the hole, is then placed into the hole and
rivetted or compressed, so as to fill both the screw thread and nicks so that it
cannot be withdrawn as the screw-thread will keep it from moving inwards or
outwards and the nicks will prevent it from turning round in the screw-thread.
I find this makes an exceedingly efficient and neat closing of the hole A*, though
I may adopt other means for this closing if desired.
In many of the joints in cycle frames as at present constructed the hole A*
would be necessary to enable the mandrel to be applied, operated and withdrawn,
though in some cases this would not be necessary, as for example where there
was a clear opening opposite the end of the tube to be jointed, or where the tube
can be got at from its other open end and a long mandrel employed.
When the mandrel C and nut D) are in place I insert hard steel segments E
of a suitable size and taper; these lie in the annular space between the mandrel
and the interior of the tube B, as indicated in Figure 2 and are forced out by
the tapered mandrel C which is rotated by its squared end C¹ or other means
as already explained. The operation is similar to that of an ordinary tube
expander but the mandrel is self-feeding, the thread C² being of so fine a pitch
that the rotating of the mandrel and the operation of expanding provides a
suitable inward movement or feed within the screw nut, thus gradually expanding
the segments, which in their turn force out the end of the tube B making it a
tight fit against the inside of the socket A¹ as shown in Figure 3.
I find that the chief pull upon the nut is during the first operation of expanding
the tube and to prevent the nut from slipping I may apply clamps--preferably of
wood outside the tube so as to clamp tight upon the nut.
When the tube B has been expanded into the socket A¹ the mandrel C may be
slackened by unscrewing it from the nut D, the segments E removed and other
segments F, Figure 3 inserted in their place. These segments F are provided
with hardened points F, Figures 3 and 4, which when the segments F are forced
outwards by the operation of the mandrel, as already described in relation to
the segments E, force outwards portions of the tube, B, thus producing
conical projections B¹ upon the tube B which in their
conical indentations A5 upon the inside of the socket A', thus
the tube B from turning or becoming loose in the socket A¹.
of these points F' may be varied if desired, but I have obtained
results with those indicated in Figures 3 and 4 of the drawings.
operation being thus completed the mandrel C is again slacked back and the
segments F removed.
turn
form
preventing
The 'shape
satisfactory
The second
A liner G is now inserted into the tube B reaching preferably somewhat further
into that tube than the end A2 of the socket A¹ so as to support the tube B
somewhat beyond that point as indicated in Figure 5. For the liner I may use
a nut of small diameter which would fit the liner and not the tube and could be
knocked out when the operation was finished. It may be used for the liner at
one end of a tube and then moved to the other end to fix the other liner, and
afterwards be knocked out.
A fresh set of segments H are now inserted, each containing a roller H₁ lying
loosely in slots in the segments so that each roller bears at one side upon the
mandrel C and upon the other side upon the interior of the liner G. The
mandrel is now again operated, expanding the liner firmly against the tube B
and thus finally and securely fixing it and generally supporting the whole joint,
which is thus smoothed and finished off inside.

page_text: The segments H may be made of sufficient length to operate upon the whole
length of the liner or only upon a portion thereof, and may if desired be made
larger at the enlarged portion so as to produce the shape shown in Fig. 5.
The projections F of the segments F may be parts of the same metal, but are
preferably separate and separately hardened and may be provided with screwed
stems and screwed into place as shown in Figure 4. The segments F may or
may not be hardened, though generally, it is preferable to have all the segments
hard.
When the last operation is completed the mandrel and nut can be withdrawn
and the hole A plugged as already described.
Where owing to the reduction in the diameter by the insertion of the liner G
difficulty would be experienced in removing the nut D, the latter may be made
in segments or with an expansible part or spring, or other holding device, or
it may be left in the tube; for the latter purpose it may be made of light métal
or alloy so as not to add any serious amount to the weight.
t
Where the nut D is intended to be left permanently in the tube it may be
used for strengthening purposes at the joint and the socket A¹ may if desired
extend so as to overlap the nut to a greater or less extent; where the nut is
intended to be removed it may be made entirely or partly of readily fusible
material, so that it can be melted out, a convenient arrangement being to recess
the outer surface of the nut and cast in a band of suitable metal which can
afterwards be. melted out without damaging the joint.
The separate parts and segments are employed because a complete tool such as
an ordinary tube expander could not be used in joints such as these, as it could
not be got in or out of the joint. The instrument which I have described and
employ is only complete when it is in position inside the tube, the various parts
being as stated applied and removed separately.
The process above described I find to give the most satisfactory results in
practice, but I may adopt the method described in my Provisional Specification,
and by using balls in the segmental pieces or using a cone or ball race upon the
mandrel instead of the points F1, I may form annular depressions in both tube
and lug and also in the liner if desired, or I may use these annular depressions in
addition to the conical depressions previously described. I may also vary the
order in which I use segments, as I may for example as described in my Pro-
visional Specification use the roller-containing segments first instead of last,
or both first and last and instead of forming the lug with a tapered socket A¹, the
socket may be parallel, the taper being formed in the process of making the
joint and the liner may be dispensed with where not required.
The separate processes above described may be carried out simultaneously at
a, single application of the tools, if these latter be suitably constructed for the
purpose.
I am aware that the formation of annular grooves for the purpose of making
a tubular joint is not new and that in Crowden & Brown's Specification No. 5491/88
means were described by which a mandrel and balls or rollers were employed
for this purpose; consequently I wish it to be understood that I make no claim
for anything described and claimed in that specification.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
1. The method or process of making a tubular joint consisting in inserting a
nut such as D into one. of the tubular members screwing a mandrel into the
nut and by means of segments and rollers balls or points such as described
forcing the two members into intimate contact substantially as described and
illustrated in the accompanying drawings.
2. An instrument or apparatus for making tubular joints comprising a mandrel
such as C C² nut such as D segments such as E, F, F¹ HH' the whole constructed

page_text: and operating substantially as described and illustrated in the accompanying
drawings.
3. A tubular joint consisting of a tapered lug or socket such as A¹ a tubular
member expanded inside the socket and forced at certain parts into the substance
of the socket and a liner such as G also expanded substantially as described and
illustrated in the accompanying drawings.
4. In the making of a tubular joint of the nature described the employment
of a fine-thread-nut such as D inside one of the tubular members which serves
as a purchase for the mandrel and also as a means of feeding the mandrel during
the expanding operation.
5. In the making of a tubular joint of the nature described the combination
with one of the tubular members of a nut, which is used as a means of feeding
the mandrel during the operation of making the joint and thereafter remains
permanently in the tube.
6. In the making of a tubular joint as herein described the employment of a
nut such as D a portion of which is formed of material fusible at a temperature
below that of the portions of the joint for the purpose of the removal of the
nut.
7. In the making of a tubular joint of the nature described the employment
of an expanding instrument or apparatus the parts of which are applied and
removed separately the various parts being together and in complete operative
connection only when inside the tube, substantially as described.
8. In the making of a tubular joint as herein described the method or means
of closing the hole A substantially as described.
Dated this 27th day of October 1897.