Improvements in Electrical Couplings.
Year: 1888

page_text: Date of Application, 14th May, 1888
Complete Specification Left, 14th Feb., 1889
Complete Specification Accepted, 30th Mar., 1889
Improvements in Electrical Couplings.
I, JOHN HUBERT DAVIES of 3 Burry Terrace, Westbourne Square, Paddington,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in Electrical Couplings.
My arrangement provides an universal electrical coupling, suitable for use in
electrically joining railway carriages and the like, which is easily and efficiently
locked and unlocked, the contact pieces being so arranged that electrical connection is
made as the two halves of the coupling are pressed together.
"The couplings may be arranged so as each to connect up one, two, or more electrical
conductors; but in all cases the separate halves of the coupling are to be exactly alike
so as to insure interchangeability. One form of contact pieces that I use consists of a
plug and a socket on each half of the coupling, the plúg on each half fitting into the
socket on the other half; these plugs and sockets may be split so as to improve the
contact. If only one electrical connection is to be made each half coupling may be
provided with a plug and a socket electrically connected together and to the leading
in cable. If two electrical connections are to be made the plug and socket in cach
half coupling are electrically connected to two leading in cables and insulated from
each other. If four electrical connections are to be made two plugs and two sockets
would be provided in each half coupling. Instead of using these plug and socket
contact pieces I may employ other forms such as flat springs which are arranged to
press against an inclined metallic face, each half coupling being provided with an
equal number of springs and inclined metallic face pieces arranged as in the case of
the plug and socket contacts.
These contact pieces are suitably supported by insulating material, such as paraffined
wood or cement, carried in an outer case of a cylindrical form with its axis parallel
to the axis of the plugs and sockets and consequently coincident with the direction in
which the half couplings have to be moved to complete the electrical connection. The
outer end of this cylindrical case may be reduced in size and made of any suitable
form to allow of the entrance of the leading in cable or cables. The other end of the

page_text: cylindrical case is increased somewhat in outside diameter at its extremity so as to form
a shoulder against which rests a metallic ring with a milled edge carrying two catches
at opposite ends of a diameter; these catches project from the ring in a direction
parallel to the axis of the case and are so formed as to engage with two similar
catches on another half coupling when the two are pressed quite together so as to
properly complete the electricial connections. To separate the two halves of the
complete coupling the rings on each have to be turned in opposite directions round
the cases when the catches will disengage and the halves can be drawn apart. At
the side of the ring away from the shoulder on the case a ring spring of rectangular
section is placed, the larger dimension of the rectangular section being preferably in
the radial direction; this ring spring is sprung into a groove formed in the cylindrical
case and is at one end fastened to the ring and at the other to the case.
venient way of holding the ends of the spring is to bend them over slightly and drop
them into slots formed in the ring and case respectively. This ring spring tends to
keep the ring and catches in the "locked" position, and being dropped into the
groove in the case, above which it projects, it also forms a second shoulder to support
the ring carrying the catches.
A con-
To make the coupling completely watertight each half is provided with an india-
rubber ring at the contact end of the case, which india-rubber rings press together
when the coupling is closed.
To support a free half coupling I may use a "dummy half similar to the ordinary
half in its essential parts but having no cable attached; or, if the free ends of a
double cable are required to be joined the "dummy" half coupling may have its
contact pieces electrically connected.
1000

page_text: 1, JOHN HUBERT DAVIES, of 3 Burry Terrace, Westbourne Square, Paddington, W.,
Electrical Engineer, 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 improvements in electrical couplings.
My arrangement provides an universal electrical coupling suitable for use in
electrically joining railway carriages and the like, which is casily and efficiently
locked and unlocked, the contact pieces being so arranged that electrical connection
is made as the two halves of the coupling are pressed together.
The couplings may be arranged so as each to connect up one, two or more electrical
conductors; but in all cases the separate halves of the couplings are to be exactly
alike so as to ensure interchangeability. One form of contact pieces that I use
consists of a plug and a socket on each half of the coupling, the plug on each half
fitting into the socket on the other half; these plugs and sockets may be split so as
to improve the contact. If only one electrical connection is to be made each half
coupling may be provided with a plug and a socket electrically connected together
and to the leading in cable. If two electrical connections are to be made, the plug
and socket in each half coupling are electrically connected to two leading in cables
and insulated from each other. If four electrical connections are to be made two
plugs and two sockets would be provided in each half coupling. Instead of using
these plug and socket contact pieces I may employ other forms such as flat springs
which are arranged to press against an inclined metallic face cach half coupling being
provided with an equal number of springs and inclined metallic face pieces arranged
as in the case of the plug and socket contacts.
These contact pieces and cables are suitably supported by insulating material such
as paraffined wood or cement carried in an outer case of a cylindrical or other form
with its axis parallel to the axis of the plugs and sockets and consequently coincident
with the direction in which the half couplings have to be moved to complete the
electrical connection. The outer end of this cylindrical case may be reduced in size
and made of any suitable form to allow of the entrance of the leading in cable or
cables. The other end of the cylindrical case is increased somewhat in diameter at
its extremity so as to form a shoulder against which rests a metallic ring with a
milled edge carrying two catches at opposite ends of a diameter; these catches project
from the ring in a direction parallel to the axis of the case and are so formed as to
engage with two similar catches on another half coupling when the two are pressed
quite together so as to properly complete the electrical connections. To separate the
two halves of the complete coupling the rings on each have to be turned in opposite
directions round the cases when the catches will disengage and the halves can be
drawn apart. At the side of the ring away from the shoulder on the case a ring

page_text: spring preferably of rectangular section is placed, the larger dimension of the rect-
angular section being preferably in the radial direction this ring spring is sprung
into a groove formed in the cylindrical case and is at one end fastened to the catch
ring and at the other to the case. A convenient way of holding the ends of the
spring is to bend them over slightly and drop them into slots formed in the ring and
case respectively. This ring spring tends to keep the ring and catches in the "locked."
position, and being dropped into the groove in the case, above which it projects, it
also forms a second shoulder to support the ring carrying the catches.
To make the coupling completely watertight each half is provided with an india-
rubber ring at the contact end of the case, which india-rubber rings press together
when the coupling is closed.
To support a free half coupling I may use a dummy" half similar to the ordinary
half in its essential parts but having no cable attached; Or if the free ends of a
double cable are required to be joined the "dummy" half coupling may have its
contact pieces electrically connected.
°
In order that my invention may be the better understood I now proceed to describe
the same in relation to the drawings hereunto annexed reference being had to
the letters and figures marked thereon. Like letters refer to like parts in the several
figures.
Figures 1 and 2 are sectional views of a half coupling in planes at right angles
to one another.
Figure 3 is a plan of the same.
Figures 4 and 5 show an elevation and plan of the spring ring...
Figures 6 and 7 show a section and plan of the catch ring.
Figures 8 and 9 show a section and plan of the coupling having flat spring
contacts.
The shading showing the cement in figure 2 is omitted in figures 1 and 3 to afford
clearness of illustration.
In figures 1, 2 and 3 A is the outer metal case in which are supported and insulated
by means of cement E the connecting split plug B and the connecting socket C.
The connecting cables D are soldered into sockets in the ends of the plug B and
socket C. F is a catch ring as shown in figures 6 and 7 carrying two catches G G³,
which catch ring is so constructed as to turn easily behind the shoulder on the case A,
and is kept in place by the spring ring H, which is sprung into the groove h. This
spring ring H is cut through at one point and the ends are turned up at right angles
in opposite directions to one another, so that one projecting end engages in a slot in
the catch ring while the other engages in. a similar slot on the case A, suitably placed
to cause the ring F with its catches G G¹ to remain in a normal position. The two
catches G G on the catch ring F engage with similar catches on the opposite half
coupling when the two are pushed together. The edge of the ring F may be milled
for convenience in grasping, or it may have several short arms screwed into it, or
any other equivalent arrangement to serve this purpose. When the two half couplings
are pushed together, the plug B in each half engages with the corresponding socket C
in the other half, and the inclined faces of the catches G G! cause the rings F to turn
round the case for a short angular distance against the action of the spring ring H
until the two halves are forced home, when the catches spring back over
another.
one
In order to make the coupling watertight, I provide an india rubber ring L, which
slightly projects above the connecting face of each half coupling, so that when the
two halves are pressed together, the india-rubber rings will be compressed, thus
hermetically scaling the coupling.
It is obvious, to release the coupling, the rings F must be turned back a short
listance in an opposite direction to that above described, until the catches G G¹
become disengaged.
I may use any cement for insulating and supporting the connecting sockets and
plugs and cables but such cement may be preferably Portland cement either pure, or
mixed with other material, as is frequently done, and impregnated with paraffin wax

page_text: or similar material to render it impervious to moisture and improve its insulating
properties. Instead of cement I may use a wooden block suitably fastened into the
case A and impregnated with paraffin wax or other suitablo material.
A modified form of connection is shown in figurés 8 and 9, whero in place of the
plug B in figures 1, 2 and 3 I may use a pair of springs B attached to a metal base
with a socket for cable connection, and V shaped lips C having also a socket for
cable connection' in place of the socket C. These springs B engage with the V shaped
lips on the corresponding opposite half of the coupling, the sockets at the ends of
the springs B and the lips being supported by an insulating plate E of ebonite or
other suitable material which is fixed in the case A. J and K are respectively a lug
and a recess to engage with a similar lug and recess on the opposite half coupling to
ensure the two going together in the proper position.
The other parts of this form of coupling are precisely similar to that illustrated in
figures 1, 2 and 3.
I make the dummy half coupling for holding a free half coupling of a case
provided with a flange or lugs for fixing up conveniently and having contact pieces
similar to those in the ordinary half coupling but with no connection to cables. It
is not necessary that the dummy should have a movable catch ring as two fixed
catches similar to those shown at G G¹ will be sufficient. If necessary the connecting
contact pieces of the dummy may be arranged so as to electrically connect together
the two ends of the cable.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1st. An electrical coupling consisting of two duplicate half couplings, each
carrying plug and socket terminals of one two or more circuits mounted in cement
or insulating material within an outor case by which electrical contact may be effected
by the couplings being pressed together, until locked in position by the engagement
of spring clutches, one into the other, as herewith illustrated and described.
2nd. In an electrical coupling the spring clutch consisting of a ring F with
catches G G mounted thereon, in combination with the spring H or its equivalent,
substantially as described.
3rd. In an electrical coupling the combination of an india-rubber washer on the
face of the half couplings with a spring clutch locking joint to make a secure water-
tight joint between the half couplings.
4th. In an electrical coupling the method of supporting electrical contacts and
conducting cables by Portland cement, pure or mixed with other material impregnated
with paraffin wax or the like, substantially as described.
Dated this 14th day of February LOOY.
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicant.