Improvements in Electric Plug Connectors.
Year: 1898

page_text: Improvements in Electric Plug Connectors.
ALBERT EDGAR TANNER, Engineer, 563, Stretford Road, Old Trafford, Manchester,
GEORGE WILLIAM Lowcock, Engineer, 40, Seymour Grove, Old Trafford,
Manchester, do hereby declare the nature of this invention to be as follows:--
This invention relates to improvements in plug connectors for use in electricity
distribution, making their use on high voltages with even considerable currents,
practicable, and rendering them safer for the user, less dangerous as a source of
fire, and less deteriorating in themselves.
The above improvements are effected by combining with a connector socket a
quick break switch, the whole being so arranged that when the plug or detachable
part is inserted an electrical connection is first made by means of rubbing contacts
or otherwise, and then the electric current is turned on by means of the switch
which is actuated by the plug.
In withdrawing the plug for disconnection the switch is first turned off by the
act of withdrawing the plug and then the rubbing contact is disconnected.
The switch may be either single or double pole, but preferably double pole and
suitable fuses may also be arranged in connection with same, with the whole
mounted as desired, preferably, but not necessarily in a watertight iron case.
1000
ALBERT E. TANNER.
GEO. W. LOWCOCK.
Improvements in Electric Plug Connectors.
ALBERT EDGAR TANNER, 78, King Street, Manchester, Engineer, GEORGE
WILLIAM LOWcock, 78, King Street, Manchester, 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 plug connectors for use in electricity
distribution, making their use on high voltages with even considerable currents
practicable, and rendering them safer for the user, less dangerous as a source of fire
and less deteriorating in themselves.
The above improvements are effected by combining with a connector socket a
quick break switch, the whole being so arranged that when the plug or detachable
part is inserted an electrical connection is first made by means of rubbing contacts

page_text: or otherwise, and then the electric current is turned on by means of the switch
which is actuated by the plug. In withdrawing the plug for disconnection the
switch is first turned off by the act of withdrawing the plug and then the rubbing
contact is disconnected.
The switch may be either single or double pole, but preferably double pole and
suitable fuses may also be arranged in connection with same with the whole
mounted as desired, preferably, but not necessarily, in a water tight cast iron case.
The accompanying drawing Figs. I, II III and IV show in detail one form of
our double pole improved plug connector.
C is a cast iron case provided with a lid so arranged that a water tight joint
can be made.
On the case are cast two bosses BB internally screwed for pipes carrying the
cables.
P is a porcelain liner on the front side of which are mounted the working parts
of the switch, fuse cte. The cables are led into terminals at the back of the base
of this porcelain liner.
On the case a boss D is also cast screwed outside for the cap E.
This boss has a hole cast or otherwise made in it for the insertion of the plug P
and we prefer to make the hole of the same shape as the section of the plug
shown in Fig. IV. The object of making the hole of this shape is to insure the
plug being inserted so that in the case of continuous current, the polarity of each
lead connected to the plug may always be the same.
The object of the cap E is to secure the plug in position after insertion.
We also construct a cap similar in general design to the cap E but without a
hole in it for stopping the plug hole in the case when the fitting is out of use. This
cap we prefer to attach to the fitting by means of a short chain.
F, F, F, F, are fuse terminals, the one pole being separated from the other by means
of the porcelain partitions p, p, which form part of the liner referred to above.
S, S, is a double pole switch with spring break.
T, T, are small tappets made solid with or rigidly attached to the levers of the
switch. The object of these tappets is explained below.
P, is the plug to which are connected at the terminals t, t, the supply leads
for the fitting which it is desired to connect to the mains.
""
"
The leads may be of the ordinary "twin flexible" but we prefer to use a "twin
flexible armoured with metal wire or tape of the kind known as
"Ferflex
armouring.
The plug itself is made of ebonite, "ambroin." porcelain or other like insulating
substance. On the upper half we fix to the sides plates of brass or copper KK
which are extensions of, and electrically connected to, the terminals t, t. These
plates make rubbing contact with the lower terminals of the switches. On
these lower terminals we fix small plates of brass or copper arranged to form a
spring contact as shown in Fig. I of the drawing.
The action of the plug connector is then as follows:-
When the plug is inserted, the side plates K K first make contact with the lower
terminals of the switch which are then "dead." and as the plug is inserted further
the shoulders XX engage the tappets TT and thus close the switch S. S. The
lower switch terminals are then "alive" and the supply leads which are electrically
connected to them in the manner described above, are thus connected to the
mains.
When the plug is withdrawn the shoulders X'X' engage the tappets T, T. and
open the switches before the contact of the plug terminal plates with the lower
switch terminals is broken.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we hereby declare that
what we claim is:-
I. The construction of a plug connector in such a manner that when the plug or

page_text: detachable part is inserted an electrical connection is first made with the "dead"
terminals of a quick break switch which are subsequently made "alive" by the
action of the further insertion of the plug or detachable portion closing the switch.
II. The construction of a plug connector in such a manner that when the plug
or detachable portion is withdrawn the terminals of a quick break switch which
make electrical connection with the terminals of the plug or detachable portion
are, by the action of the withdrawing of the plug opening the switch, made “dead”
before that electrical connection is broken.
III. The construction of a plug connector substantially in the manner shown on
accompanying drawing Figs. I, II, III and IV and in the manner herein before
described.
Datal thin 10th low of Tanum 1800
ALBERT E. TANNER.
GEO. W. LOWCOCK.