Year: 1894

page_text: Date of Application (in United Kingdom), 27th June, 1894
Complete Specification Left, 27th June, 1894-Accepted, 1st Sept., 1894
tubes, capable of movement, is a recognised necessity and there have already been
produced for this object various kinds of metallic couplings.
The question, notwithstanding, is still an open one as in no metallic coupling do
those parts which allow of movement being made possess all the properties which
are to be desired, namely:
Great simplicity.
:―
A perfectly safe and strong joint.
Great durability.
Ease in handling.
The revoluble screw-joint, a cross section of which is shown on the drawing, will
however correspond to all these requirements. By means of a screw thread two
pipes are revolubly connected with one another, and in order that each of the pipes
may be well guided by one another and a secure joint be obtained, they overlap
each other beyond the screw thread, forming first of all a hollow space and then
coming again in contact with one another so as for the second time to form a
cylindrical guide way for one another. (The first guide way was formed by the
screw thread.)
The one piece of piping is enlarged in front of the screw thread to form a
cylindrical collar or sleeve (=), the other is provided behind the screw thread with
a flange (w) forming on the inner side, which is turned to the collar or sleeve, a
sharp cone. Before both pieces of the piping are screwed together there is placed
upon this cone, being stretched over a little rail or bolster (c), an elastic packing
ring (b) of wedge-shaped cross section, the interior conical surface of which is the
same slope as the conical flange (w). This packing ring is made a little too small
in diameter so that when placing it in position it has to be pulled out and therefore
receives a certain amount of stretch. The exterior diameter of the packing ring
when in position is a little smaller than that of the cylinder (2) so that it does not
touch the same and consequently does not in any way act as a brake upon the joint,
besides which any water of condensation which there may be in the joint can
run off.
In order to put the packing ring under pressure, holes (a), or grooves, are
made in the screw thread by means of which the pressure from the piping passes
directly behind the ring. It is not sufficient to allow the pressure to act along.

page_text: the screw thread since the resulting throttling is so great that the ring is not
pressed to with the requisite energy.
If pressure arises bebind the ring, the ring is then pressed outwardly upon the
cone (w), becomes thereby enlarged and wedges itself in between the cone (w) and
the cylinder (2) with absolute security and will also act as packing even if the
ring or the packing surfaces have become somewhat injured or have become
somewhat spoiled by any dust or dirt which may have come from the piping.
This perfectly safe packing is not to be attained by means of a cylindrical ring.
Owing to the ring becoming wedged between the cone (w) and cylinder (z) the
guide way () becomes relieved. The india-rubber ring, as soon as pressure
enters into the joint, will therefore form the second guide way and consequently
the metallic guide way (f) is thereby spared and preserved against being worn
away..
When the pressure ceases the ring then retires to its original seating on the
small pillow (c) and consequently comes out of contact with the cylinder (2). The
screw thread of the parts facts therefore as guide ways for the parts of the joint
when in an empty condition and as then no braking action takes place the parts are.
very easily revoluble and consequently the coupling can be handled without
trouble.
As the ring does not expand in the hollow space receiving it right up to the
packing joint (f) it is not so exposed to being worn away as known packing rings
are which have a cross section of Lor U shape which, lying directly on the
packing joint, become wedged by the pressure into it and become worn away in
shreds owing to the revolutions of the joint.
A very essential advantage of my joint is further that there is no need of any
loose parts or pieces for bringing home the ring to its place and for holding it
tight, whereby the greatest simplicity and security of action are attained.
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 :-
An improved coupling device for the pipes of railway trains, consisting of
revoluble screwed pipe joints which have a conical flange (e) on one of the two
pipe ends, behind the screw thread, and a collar or sleeve on the other pipe end,
capable of sliding over the flange (w), so that by means of an intermediate
india-rubber ring, of wedge shaped cross section, which can be compressed by
means of the pressure prevailing in the interior of the pipes, and which pressure is
transferred through holes (a) or grooves in the screw thread, the automatic
packing of the parts will result.
Dated June 26th 1894
W. P. THOMPSON & Co.,
Agents for the Applicant.