Year: 1887

page_text: Date of Application, 3rd May, 1887.
Specification Accepted, 10th June, 1887.
I, EDMUND COGGSWELL CONVERSE, residing at 223, Ridge Avenue in the City of
Allegheny, County of Allegheny, and state of Pennsylvania, one of the United States
of America, Manufacturer, 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 :-
My invention relates to couplings for metal tubing, its object being to form a
coupling whereby the several lengths of tubing can be connected without cutting into
and weakening the tubing as is the case where they are connected by screw threaded
couplings or sockets. Where a screw thread is cut into the metal tubing it is so
weakened at the part threaded that to enable this part to withstand the necessary
internal pressure or any longitudinal strain or lateral or bending strain the tubing is
formed much thicker than is necessary for the unthreaded portion of the tubing. It
is evident that this increased thickness of the tubing necessarily increases not only its
cost, but on account of its increased weight, also adds much to the expense of
transportation. For this reason a coupling by which the lighter metal tubing can be
securely connected, so as to withstand not only the internal pressure of the water or
other liquid, compressed air, or gas confined in or passing through it, but also any
longitudinal strain consequent to the expansion and contraction of the tubing or lateral
bending strain, is much sought after.
Another object of my invention is to form a coupling wherein the interior face of
the tubing and coupling are even, and the inner surface of the line of tubing is
smooth thus doing away with the friction found in the ordinary couplings on account
of the ends of the tubing not meeting each other, side currents being formed in the
fluid passing through the tubing at each joint.
My invention consists, first, in a coupling collar or sleeve for tubing having an inner
central ring and an annular calking recess at each end for the reception of lead or
other calking or packing material, said calking recesses having inwardly flaring sides
to hold the calking material more securely in place and enable it to withstand without
displacement any internal pressure from the fluid in the tubing; second in combining
with tubing having one or more lugs or similar connecting devices this coupling collar
or sleeve provided on the interior with a central ring against which the ends of the
TD 077

page_text: tubing butt or bear, proper seats or recesses on either side of said ring within which
the lugs on the tubing engage, and annular calking recesses at each end beyond such
seats or recesses whereby after the connection between the tubing and collar has been
effected the annular recesses may be filled and calked or packed, and the calking
material will lock the lugs in their seats and surround the tubing above the locking
devices;
and finally in forming the inner faces on each side of the central ring of the
collar tapering so as to compress or "bind" around the end of the tubing and round
up to proper shape if its edges become bent in transportation or handling.
it
To enable others skilled in the art to make and use my invention I will describe its
construction and manner of use, referring for that purpose to the accompanying
drawings, in which ;-
Figure, 1, is a sectional view of the coupling collar showing one tube connected
therein and the other tube in full lines ready to enter the collar.
Figure, 2, is a cross section on the line, x-ax, of fig. 1.
Figure, 3, is a perspective view, partly broken away, of the coupling collar.
Figure, 4, is a longitudinal section of the tubing showing the connecting lugs
expanded from the body of the tubing and
Figure, 5, is a sectional view illustrating another form of coupling collar.
Like letters of reference indicate like parts in each.
The coupling collar or sleeve, A, is preferably cast to shape, though it may be rolled
or forged and turned, if desired.
It is preferably provided with the annular ring or projection, b, midway between
the ends, so as to form on either side of it an annular shoulder, against which the
ends of the tube-sections, C, C, butt or bear. The ring is made the same height as
the thickness of the metal in the tubing, so that a smooth interior is obtained for the
passage of the fluid to be connected, and no opportunity is afforded for the pressure of
the fluid directly against the ends of the tubing. By having the inner surface
smooth or flush as above described, the friction of the fluid in passing through the
coupling is entirely overcome, and practical experience shows that from, 10, to, 25 per
centum less power is required to force the fluid through a line of tubing thus connected
than when the ends of the tubing do not meet, and consequently form an annular
space in the coupling between the ends of the tubing by which "riffles
or side
currents are formed. The inner faces, d, of the collar extend out a sufficient distance
on either side of the central ring, b, to give a strong brace to the ends of the tubing,
around which they fit neatly, being preferably formed slightly tapering, so as
to compress or bind the ends of the tubing around their entire circumference, thus
rounding up the tubing, if bent out of shape, and enabling the body of the collar to
support it against internal pressure strain. These inner faces may be divided into
sections if desired.
"
Between these inner faces, d, and the ends of the collar are the annular calking
recesses, f, for the reception of the lead or other calking material, these calking
recesses being preferably formed inwardly flaring, being of larger diameter at the base
or between the base and the mouth than at the mouth, and therefore holding the
calking material more securely in place and preventing its displacement from any
internal pressure strain. Within the coupling collar are the locking seats, g, which
are formed either between the inner faces, d, and the calking recesses, f, or entirely
within the inner faces, d, as shown, this latter construction being preferred, as the
inner faces can be made larger and envelope a greater portion of the tubing, so
giving to them a greater support, and reducing the calking recesses so that they
require but little lead or calking material.
This is covered in an application for English Patent filed by me of even date
herewith. The seat, g, may be of any suitable form, the seat preferred by me being
shown in the drawings and being formed of a rib, h, back of which the body of the
collar is hollowed out or depressed as at, e, for the reception. of the lug, c, on the
tubing, the lug catching behind this rib, and thus securely locking the tubing within
the collar against longitudinal or drawing strain. The seat is preferably formed with
a space, 1, through which the lug in the tubing passes, and a rib, h, on either side of

page_text: this space, so that the tubing can be turned in either direction to lock it within the
collar. The inner faces of the ribs, h, may extend at a slight angle from their outer
ends inwardly toward the ends of the seats, so that the lugs in the pipe may travel
up the incline thus formed and press the end of the tubing against the end of the
central ring.
The number of locking lugs and seats formed on each end of the tubing and in the
collar will depend on the diameter of the tubing to be connected, two such locking
devices at each end being generally, sufficient, except in connecting large tubing when
three or more may be employed.
In figuro, 5, is shown another form of coupling collar in which the central ring, b,
is dispensed with and the inner face of the coupling extends between the calking
recesses. Where the locking connections above described are employed the lugs fitting
in the locking seats will hold the tubing in proper position in the coupling collar so
that the ends of the tubing meet within the inner face between the calking recesses
and thus form the inner surface smooth or flush at the coupling. This form is not
however, considered as desirable as where the central ring is employed.
The lugs, c, are preferably riveted on the tubing, as this does not require its
reheating, though they may be welded thereto or expanded therefrom as shown in
figure, 4, neither method injuriously affecting the tubing, as the lugs are supported
within their seats and the calking material enters within the seats back of the lugs
and entirely fills the calking recess above the locking connection, so that it prevents
any leakage, even where there is an imperfection at the lugs.
The form of the coupling collar may be varied as shown in the several figures, the
collars shown in figures, 1, and, 2, having a thick body in order to retain the gas
which is liable to leak through a thin body of cast metal when under extremely high
pressure, and when the coupling is employed on gas mains a thick body being
employed, and, if desired, the collar being boiled in paraffine to fill or close the pores
of the metal before it is used.
In figure, 5, the collar is formed thinner having a curved or double ogee shape, and
a depressed portion, p, in the centre, this form of coupling being generally employed
on water or other liquid mains. The metal may be increased over the locking seats as
at, r, if desired.
In connecting tubing by my improved coupling collar or sleeve the ends of the tube
sections are inserted into the collar, the lugs, c, passing through the spaces, 1, and the
ends passing up the tapering inner faces, d, being brought to proper cylindrical form
and bearing against the central ring, b, and the tubing is then turned within the collar
either to the right or left, so as to lock the lugs behind the ribs, h, the tubing and
collar being held by this connection against longitudinal or drawing strain. Where
the inner faces of the ribs, h, are formed inclined as above referred to, the ends of the
tubing are pressed against the central ring the lugs, c, travelling up the inclined ribs,
and at the same time the tapering inner faces, d, are caused to bind tightly around the
ends of the tubing for the purpose above set forth. Where the tubing can not, be
turned for any reason the collar can be turned on it, thus making the locking
connection. The melted lead or other calking or packing material is then poured into
the annular recesses, f, and calked or solidified in the usual manner, and the coupling
is made. The calking material, as it is poured into the annular recesses, enters into
the spaces, 7, between the ribs, h, and around the lugs, c, within the locking seats, g
and thus locks the lugs within the seats and fills the calking recesses between the
locking seats and the mouths or ends of the collar, entirely surrounding the tubing in
this space above the locking connection. It thus prevents any leakage at the coupling,
even though the ends of the tubing do not fit close to the central ring or there is any.
imperfection at the lugs through which the water or other liquid compressed air, or
gas might escape, forming an absolutely secure joint for this light metal tubing, which
has been tested to a pressure of over, 1000, pounds to the square inch without leaking.
The locking connection is sufficiently loose to provide for the slight longitudinal
movement of the lugs within their seats and so provide space for the expansion and
contraction of each length of tubing, each joint permitting a movement of about one

page_text: eighth inch which is greater than the maximum movement of each tube on expansion
or contraction. At the same time the locking connection secures the joint against any
heavy longitudinal strain, and as the body of the tubing is not weakened at or near
the ends of the collar (the lugs being below the calking material and protected by it)
there is no more liability of injury to it from lateral or bending strain at the coupling
than in the body of the tubing.
I thus obtain a coupling which is comparatively inexpensive, and by which light
metal tubing can be securely connected against all strains without weakening the
tubing as above referred to. I also obtain a smooth inner surface to the tubing and
collar when connected, so that the fluid confined has no opportunity to press through
the coupling and escape, and as the inner surface of the line of tubing is smooth or
flush, I do away with the friction caused by the usual joint and for this reason require
less power to force the fluid through the tubing. As the tubing is much thinner and
lighter than the ordinary threaded tubing employed for the same purpose, I effect a
large saving in the cost of the tubing employed, and also in the cost of shipment, an
important item with large shipments at long distances. As the collars may be secured
to the tubing when the tubing is used, they may be formed at or near the place
of shipment, thus saving the expense of long shipments the couplings generally in use
being necessarily formed and fitted where the tubing is manufactured.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. In couplings, a coupling collar, having a central ring and an annular calking
recess at each end, having inwardly flaring sides, substantially as and for the purpose
set forth.
2. In couplings for tubing the combination with tubing having one or more lugs or
other connecting devices at or near each end thereof, of a coupling collar or sleeve
provided with an inner face or faces at or near the centre thereof, corresponding
locking seat or seats at each side of said inner face for the reception of the lugs on the
tubing and annular calking recesses between said locking seats and the ends of the
collar, substantially as and for the purposes set forth.
3. In couplings for tubing, the combination with tubing having one or more lugs
or other connecting devices at or near each end thereof, of a coupling collar or sleeve
provided on the interior with a central ring, corresponding locking seat or seats on
cach side of said ring for the reception of the lugs on the tubing, and annular calking
recesses between such locking seats and the ends of the collar, substantially as and for
the
purposes set forth.
4. In couplings for tubing, a sleeve or collar having an inner central ring, tapering
inner faces on each side of said ring and annular calking recesses at each end of the
collar substantially as and for the purposes set forth.
5. In couplings for tubing, a coupling sleeve or collar provided with an inner face
or faces at or near the centre thereof locking devices for engagement with the tubing,
and annular calking recesses at the ends, said collar being boiled in paraffine to fill
and close the pores, substantially as set forth.
6. In couplings for tubing, the coupling collar herein described having the locking
recesses, g, therein, and the enlargements, r, formed on the outer surface above said
recesses, substantially as and for the purposes set forth.
1
1 1007
W. P. THOMPSON & BOULT,
Agents.