Improvements in the Jointing of Tubes.
Year: 1897

page_text: "Date of Application, 20th Aug., 1897-Accepted, 25th Sept., 1897
14972
Improvements in the Jointing of Tubes.
I, REINHARD ISIDORE ROMAN of 31 Lombard Street in the City of London,
Metallurgical Chemist, 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 relates to the jointing of tubes, and is particularly applicable
for the jointing of tubes in the manufacture of cycles.
The great difficulty experienced hitherto in building cycles in a suitable light
aluminium alloy has been the impossibility of making a good joint.
The brazing or soldering of aluminium alloys has so far proved absolutely
unreliable.
The soldering and brazing of steel is a great drawback as the seamless hard
drawn tubes are annealed by the brazing heat, and are consequently weakened
just in those places where the greatest strength is required.
Of late years all sorts of joints to avoid brazing have been tried, but so far
without success. Wedged liners, disced liners, screws, double-cut threads and
many other systems were all found after a short use to run loose and thereby
expose the rider to dangerous accidents.
Long and persevering experiments have led me to devise the following im-
proved method of jointing tubes in sockets without brazing, screwing, rivetting
or pegging, so that the joint can easily be made and also as easily undone, even
by unexperienced hands.
g
This invention, which is also applicable to the jointing of metallic tubes other
than cycle tubes, consists in the use of an internal spring locking ring or thimble
provided with a longitudinal slit having its edges turned inwards in such a manner
as to form a tapering opening adapted to fit and receive a grooved key; said key
being suitably tapered to spread forcibly said ring or thimble against the inner
surface of the tube.
The socket as well as the tube to be fitted in the same, must have absolutely
smooth and even surfaces, which are also preferably polished. Also the split
spring locking ring to be inserted therein must have a perfectly smooth (preferably
polished) external surface.
In the accompanying drawings, A is the tube which it is desired to fix into
the socket B. The tube A is inserted in the socket B and there is then intro-
duced into the interior of the tube the spring ring or thimble C which is formed
with a longitudinal slit D having inturned edges E E, so as to form a tapering
opening D as shown.
The key F is slightly tapered and has grooves G G formed in two opposite
sides to fit the beadings E E of the slit D. The key is inserted into the slit D,
the grooves G G guiding the key in its proper direction and also preventing
its falling out.
When this key is forced in, it expands the locking ring or thimble C producing
an absolutely firm joint.

page_text: The ring C expanded in all its length produces an equal pressure over the
entire surface of the lugged tube against the socket.
The pressure is calculated to be about 2,500 lbs. per square inch; the joint
consequently is nearly like solid metal.
The advantages which are obtained by the use of my improved mechanical
joints for light aluminium alloys and other metals used in cycles and similar
constructions with the object of avoiding brazing, are as follows:-
1. The joint can be easily done and undone when required.
2. The metal used for this kind of joint being neither annealed nor oxidized
by heating can be used in considerably thinner gauges, and therefore cycles can
be made much lighter.
3. By avoiding brazing, the manufacture is rendered much cheaper and much
more expeditious.
4. Any cyclist or other user of my improved joints can do his own repairs
without any difficulty..
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:-
-
1. For jointing tubes, the combination of an expanding internal spring ring
or thimble provided with a tapering longitudinal slit having turned-in beadings
or edges with a tapering key grooved to receive the beadings or edges of the slit,
substantially as described.
2. The method of fixing one tube inside a socket or the like, by introducing
inside the tube a spring ring provided with a tapering longitudinal slit with its
edges turned to fit into and receive a tapering grooved key, said key being
afterwards forced in to expand the ring, substantially as described.
3. The improved device for fixing tubes in sockets or other tubes, consisting
of the ring and key as hereinbefore described and shown in Figures 3 to 6 of the
accompanying drawings.
Dated this 20th day of August 1897.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.