Year: 1896

page_text: I JOHN HENRY TUCKER Electrical Engineer 16 Oozells Street, Birmingham
do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in electric couplings, commonly known as
wall plugs and sockets; and has for its principal object, to prevent the safety fuse
when fused under an excess of current, falling across the two poles of the coupling
and thus causing a short-circuit.
In carrying out this invention I may employ in the socket, two tubular contacts
in axial alignment with each other, or I may employ one tubular contact only,
axially with which is fixed a stud or pin which forms the other contact; both
contacts being fixed upon a suitable insulating base.
In order to prevent short-circuiting by the molten metal of the safety fuse,
I entirely separate the fuse from the opposite pole to that to which it is attachel,
by forining preferably the upper of the two tubular contacts as a bridge, having in
the centre the tubular contact, projecting radially from which are two wings which
form a wall or walls vertical with the base, and, when the cover is un, divides the
space inside into two compartments; in one of which is fixed the safety fuse
connecting one terminal or pole and the bridge; and in the other compartment is
placed that portion of the lower tubular contact which serves as the other terminal
or pole. The tubular portion of the bridge may be extended downward to the
base on the side towards the fuse compartment (provision being made for properly
insulating it from the lower contact), or I may close this space by means of a
suitable insulating material. Whichever method I adopt my object is to effectually
prevent any possible connection between the safety fuse and the lower or iuner
contact, except by means of the plug.
This plug has two cylindrical contacts at distances apart corresponding to the
tubular contacts of the socket, said contacts being insulated from each other, and
respectively connected to terminals fixed conveniently in the head of the plug.
Should I prefer to use a central stud or pin, in the place of the lower tubular
contact, the usual form of plug for such an arrangement of contacts would be
employed. For the purpose of adjusting the grip of the tubular contact upon the
plug, I divide the ring, preferably at one of the wings, and insert a screw to prevent
the said ring being forced open and thus making an imperfect contact with the
plug.
It is obvious that the tubular contact aud the radially projecting wings may be
formed of one or more parts, and be constructed either entirely of metal, or partly
of metal and partly of an insulating material.
Dated this Thirty-first day of January Eighteen hundred and ninety-six.

page_text: An Improved Electric Coupling.
I, JOHN HENRY TUCKER, of No. 16, Oozells Street, in the City of Birmingham,
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 those electric couplings which are commonly known as
wall plugs and sockets, and the particular object of this invention is to prevent the
safety fuse, when fired under an excess of current, from falling across the two poles
of the coupling and thus causing a short circuit.
For the purposes of this invention I may employ in the socket two tubular
contacts in axial alignment with each other or I may employ one tubular contact
only axial with which is fixed a stud or pin which forms the other contact, both
contacts being fixed upon a suitable insulating base.
I will describe my invention by referring to the accompanying drawing on
which
Fig. 1 is a sectional front elevation of a wall socket constructed according to this
invention; Fig. 2 is a sectional plan of the same;
Fig. 3 shews the ordinary plug for the socket;
Fig. 4 is a general view of one of the tubular contacts of the wall socket shewn
in Figs. 1 and 2 and Fig. 5 is a general view of the other tubular contact of the
same;
Fig. 6 is a back elevation and sectional plan of the insulating ring which is
provided between the tubular contacts and
Fig. 7 shews the ordinary stud or pin contact which may be used with
the tubular contact shewn by Fig. 4 instead of the tubular contact shewn
by Fig. 5.
The same letters of reference indicate the same or corresponding parts in all the
figures of the drawing.
A is the usual insulating base and B and C are the two tubular contacts arranged
in axial alignment with each other and fixed to the base A. D is the connection
for say the negative pole which is connected to the base b' of the tubular contact B
by the safety fuse E. c is the connection for say the positive pole to the base of
the tubular contact C. F is the ordinary removable cover of the insulating material.
G is the plug for the said socket made with the two cylindrical contacts H and I
at short distances apart corresponding to the two tubular contacts B and C of the
Bocket, these cylindrical contacts H and I being insulated by the vulcanite or other
insulating washer J and respectively counccted to the ordinary terminals fixed in
the usual way in the head G of the plug. The plug and connection shewn by
3 is of the usual kind and forms no part of this invention.
Fig.
In carrying out my invention I proceed as follows:-In order to prevent short
circuiting by the molten metal of the safety fuse E falling across the two poles of
the coupling, entirely separate the fuse E from the opposite pole C el by forming
preferably the upper contact B as a bridge having at the centre the tubular
contact B and projecting radially from this there are two wings b b which form a
wall or walls vertical with the base A and when the cover is on the base as
in Figs. 1 and 2 these wings divide the inside space into two compartments as will
be seen by an examination of Fig. 1. In one of these compartments there is fixed
the safety fuse E connecting the terminal of the pole D with the bridge B
and in the other compartment there is placed the portion c'e of the lower tubular
contact C which serves as the other terminal or pole.
The tubular portion B of the bridge B 6 6s may be extended downward to the
'

page_text: base A on the side towards the compartment in which is a fuse E (provision being
made for properly insulating this lower portion from the upper portion C) or, and
this is what I prefer, I may as shewn in Fig. 2 close the space between the tubular
contact B and the base A by means of a ring of suitable insulating material such
as that marked K and shewn separately in Fig. 6, and which is made with a
slot k for the part of the lower tubular contact C to pass through. Whichever
method adopt my object is to effectually prevent any possible connection
between the safety fuse E and the lower or inner contact C except by means of
the plug.
It will be evident that my invention can be similarly applied to those wall sockets
in which one of the contacts is made with a central stul or pin such as L she vn
in Fig. 7 in place of the tubular contact C. In this case the usual forn of plug
for such an arrangement of contact is employed.
The second object of my invention is to so construct the tubular contact B that
its grip upon the contact H of the plug may be adjusted to compensate for wear.
This I effect as shewn by Figs. 12 and 4, that is to say, I divide the ring like
contact B preferably at that is at one of the wings an I make the ring B with
a lug through which passes a screw M into the wing so that this screw will
prevent the ring B from being forced open which might have the effect of miking
an imperfect contact with the plug. The screw M also enables the grip of the
ring B to be adjusted on the plug and thus compensate for wear.
It is obvious that without departing from the nature of my invention the tubular
contact B and the radial projecting wings may be formed of one or more
parts and be constructed entirely of metal or partly of metal and partly of an
insulating material.
Having now particularly described and ascertained the nature of my said inveu--
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. In an electric wall socket of the kind herein referred to, making one of the
tubular contacts as a bridge which divides the inner space enclosel by the cover
and the base into two compartments and so separates the two poles of the coupling
as to prevent any part of the melted fuse from causing a short circuit, substantially
as set forth.
2. In an electric wall socket of the kind herein referred to, making the size of
the outer divided tubular contact adjustable by means of a screw passing through
a lug of the same substantially as hereinbefore described and shewn by Figs. 1, 2
and 4 of the accompanying drawing for the purpose of ensuring a proper grip on
the plug.
3. The combination and arrangement of parts forming the improved electric wall
socket hereinbefore described and illustrated by Figs. 1, 2, 4, 5 and 6 of the
accompanying drawings.
4. The combination and arrangement of parts forming the improved electric wall
socket herein before described with reference to Figs. 1, 2, 4, 6 and 7 of the
accompanying drawings.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.