Improvements in Electric Switches, and in Apparatus for Connecting Electric Circuits.
Year: 1896

page_text: Date of Application, 10th Apr., 1896
Complete Specification Left, 9th Jan., 1897-Accepted, 10th Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches, and in Apparatus for Connecting
Electric Circuits.
JOSEPH DEVONPORT FINNEY ANDREWS 45 Fulham Park Gardens London S.W.
Electrical Engineer do hereby declare the nature of this invention to be as
follows:-
My present invention relates to improvements in electric switches or apparatus for
connecting electrical conductors either permanently or intermittently as may be
required. According to one form of my invention I construct the part for making
contact out of two tubes fitted one within the other so that they can slide on each
other telescope fashion, and arrange a spring around them between shoulders on
the tubes by means of which they are kept distended. I arrange a stop between the
tubes to prevent their separating beyond the desired extent; this stop may be con-
structed by enlarging part of the outer tube and expanding the end of the inner tube
into it. The conducting wire to which I desire to make connection would be soldered
into the inner tube. I may arrange the spring within the inner tube in which case I
would close over the ends of both tubes to form stops and provide a smaller tube up
the centre of the spring for making connection to the circuit wire. According to a
modified form of this contact contrivance, instead of tubes I sometimes prefer to
employ U-shaped pieces of metal fitted into each other longitudinally with the spring
or springs between them. I prefer to employ this form of my contact for electric
switches, and I mount it in a tube suitably insulated from and carried by an axle in
the bearings so that the ends of the spring contact protrude from the ends of the
tube radially and strike against fixed contacts connected with the circuit wires when
the axle is turned. I arrange these fixed contacts opposite to each other fixed in
suitable insulating material which is held into the box by a screw and nut, which at
the same time fixes the contacts by a projecting foot on each, which is held under an
insulating washer under the nut, and against which my spring contacts rest when the
circuit is open and the spring is distended. Instead of arranging the spring contacts
to rest against insulating material when the circuit is open I sometimes make one of
the fixed contacts broad so that the spring contact does not leave it, in which case I
arrange the opposite contact free from insulating material at the place the spring
contact meets it. I may arrange the switch for several circuits in which case the
fixed contacts would be arranged in a circle round the axis. I usually prefer to
encase my switch in a metal box with a suitable handle outside to turn the spring
contact within. When I wish to connect my switch to the system of wiring known
as concentric wiring, I construct a joint box of metal with tubular projections, into
which I solder the outer conductor of the concentric wire having first soldered a
ferule or tube on to the end of the conductor which fits the tubular projection and
may afterwards be soldered into it, the inner wire being carried forward to the
opening in the upper part of the box. In the lower part of my switch box I make a
corresponding opening and I provide a screw union piece between it and the opening
in the joint box. Through this union I carry the central wires of the concentric
conductors and fix them on to the fixed contacts preferably to the part by which they
are held in the switch. In the bottom of this joint box I provide a suitable insulator.
When I have several circuits, I provide a tubular projection from the joint box for
each. In some cases I arrange the one tubular projection to take two or more
concentric conductors. This joint box is applicable also to making connections

page_text: between fixed circuits of concentric conductors in which case I unite the central
conductors together inside the box in any known manner but I prefer to do so by
sinking a piece of metal into the insulator provided in the box and fixing the ends of
the central conductors to it preferably by soldering. The same joint box is also
applicable to the connection of fittings for which purpose I provide a union in
the joint box similar to that for the switch and I provide the end of the fitting with a
spring contact as previously described which makes connection on the piece of metal
in the joint box to which the circuit wires are joined. I may sometimes prefer to
combine the joint box and box of the switch or other appliance in one, in which case
I pierce the side of the switch box to receive the concentric conductor with its ferule
or tube, as described, attached, and when it is in position I may either solder the
ferule to the inside of the box which would be suitably formed and prepared for
the purpose, or I may fix it by a saddle or strap and screws. If there are several
circuits they would be similarly treated. The central wire of the concentric
conductor would be connected to the fixed contacts. This form of connection box can
likewise be modified to suit the union of several circuits together, or for connecting
a fitting for the electric lamp to the circuits as described in regard to the previous
modification, or for the insulation of a fuse which would be inserted between the
fixed contacts described in the switch box. When I apply my switch and contact
arrangements to the electric light fittings direct, I attach one of the previously
described tubular contacts to each of the fixed contacts in the box either direct or
by a piece of insulated wire according to the length of the fitting and the position
of the switch in it.
قيم
1
11000
Improvements in Electric Switches, and in Apparatus for Connecting
Electric Circuits.
JOSEPH DEVONPORT FINNEY ANDREWS, Electrical Engineer, 45, Fulham Park
Gardens, Fulham, London, S.W. do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My present invention relates to improvements in electric switches or apparatus for
connecting electrical conductors either permanently or intermittently as may be
required. According to one form of my invention I construct the part for making
contact out of 2 tubes fitted one within the other so that they can slide on each other
telescope fashion and I arrange a spring around them between shoulders on the tubes
by which they keep distended. I arrange a stop between the tubes to prevent their
separating beyond their desired extent, this stop may be constructed by enlarging
part of the outer tube and expanding the end of the inner tube into it. The con-
ducting wire to which I desire to make connection would be soldered into the inner
tube. I may arrange the spring within the inner tube in which case I would close
over the ends of both tubes to form stops and provide a smaller tube up the centre of
the spring and fixed preferably to the larger tube for making connection to the
circuit wire. According to a modified form of this contact contrivance instead of
tubes I sometimes prefer to employ U shaped pieces of metal fitted into each other
longitudinally with the spring or springs between them. I prefer to employ this form
of my contact for electric switches and I mount it in a tube suitably insulated from
and carried by an axle in bearings so that the ends of the spring contact protrude
from the ends of the tube radially and strike against fixed contacts connected with

page_text: the circuit wires when the axle is turned. I arrange these fixed contacts opposite to
each other fixed in suitable insulating material which is held into the box by a screw
and nut, which at the same time fixes the contacts by a projecting foot on each which
is held under an insulating washer under the nut and against which my spring con-
tacts rest when the circuit is open and the spring is distended. Instead of arranging
the spring contacts to rest against insulating material when the circuit is open
sometimes make one of the fixed contacts broad so that the spring contact does not
leave it in which case I arrange the opposite contact free from insulating material at
the place the spring contact meets it. "I may arrange this switch for several circuits
in which case the fixed contacts would be arranged in a circle round the axis.
I usually prefer to encase my switch in a metal box with a suitable handle
outside to turn the spring contacts within. When I wish to connect my switch
to the system of wiring known as concentric wiring, I construct a joint
box of metal with tubular projections into which I solder the outer conductor of
the concentric wire having first soldered a ferrule or tube on to the end of the
conductor which fits the tubular projection and may afterwards be soldered into it,
the inner wire being carried forward to the opening in the upper part of the box.
In the lower part of my switch box I make a corresponding opening and I provide
a screw union piece between it and the opening in the joint box. Through this
union I carry the central wires of the concentric conductors and fix them onto
the fixed contacts preferably to the foot by which they are held in the switch box.
In the bottom of this joint box I provide a suitable insulator. When I have several
circuits to the switch I provide a tubular projection from the joint box for each. In
some cases I arrange the tubular projection to take 2 or more concentric conductors.
This joint box is applicable also to making connection between circuits of concentric
conductors in which case I unite the central conductors together inside the box in any
known manner, but I prefer to do so by sinking a piece of metal into the insulator
provided in the box and fixing the ends of the central conductors to it preferably by.
soldering. The same joint box is also applicable to the connection of fittings for
which purpose I provide a union in the joint box similar to that for the switch and I
provide the end of the fitting with a spring contact as previously described which
makes connection on the piece of metal in the joint box to which the circuit wires are
joined. I may sometimes prefer to combine the joint box and box of the switch or
other appliance in one in which case I pierce the side of the box to receive the
concentric conductor with its ferrule or tube as described attached and when it is in
position I may either solder the ferrule to the inside of the box which would be
suitably formed and prepared for the purpose or I may fix it by a saddle or strap
and screws. If there are several circuits they would be similarly treated. The
central wire of the concentric conductor would be connected to the fixed contacts.
This form of connection box can likewise be modified to suit the union of several
circuits together or for connecting a fitting for the electric lamp to the circuits as
described in regard to the previous modifications or for tho insertion of a fuse which
would be inserted between the fixed contacts described in the switch box.
I apply my switch and contact arrangements to the electric light fittings direct, I
attach one of the previously described tubular contacts to each of the fixed contacts
in the box either direct or by a piece of insulated wire according to the length of the
fitting and the position of the switch in it.
When
Fig. 1 represents a spring contact in accordance with my invention C & bare two
tubes arranged one within the other so that one can be moved along the other but
prevented from separating by shoulders a a and I place a spiral spring d around them
between shoulders S. S. at the outer end of each tube and this spring is tensioned so
as to keep the tubes extended. Into the inner tube the conducting wire would be
soldered, which is effected by compressing the tubes against the spring one over the
other so that the inner tube protrudes beyond the outer when a soldering bit can be
applied with the usual flux. This contact is specially suitable for effecting the
connection of parts of electric light fittings and lengths of leading wires together.
Fig. 2 represents a modification of this contact in which the spring d is contained

page_text: within the sliding tubes and an additional tube T. is provided to effect the connection
with the leading wire by soldering. Fig. 3 represents a further modification and
consists of U shaped pieces of metal a a fitted together as shown in a rectangular
piece of tube C each U piece having a foot S. S. on one of the legs which fit into
slots in the rectangular tube and thus prevent the U pieces leaving the tube, a
spring D is provided to keep the U pieces distended. I find this to be a more suitable
form when I wish to effect connection between two fixed conductors as in the case of
a switch as shown in Figs. 4 and 5 in which case I mount the rectangular tube with
its contacts and spring in a handle H provided with suitable bearing. The fixed
contacts d d are arranged diametrically opposite embedded in an insulating material
and the sliding contacts a a when under compression are arranged to bridge from one
contact to the other thus making connection between the two. When I turn the
handle carrying these sliding contacts I move them away from the fixed contacts onto
the insulating material and in so doing they distend by force of the spring d and slide
on the insulating material and cause the break of the circuit to take place sharply.
I may modify the arrangement of the fixed contacts in the box as in Fig. 6 in which
dd² are the contacts, d being attached to the insulation ring, free from the insulating
material at the contact surface and contact d² is made broad so that as the sliding
contacts are made to turn by the handle, the one touching this broad fixed contact
slides on it in turning and causes the break at contact d to take place sharply. I may
use any other form of sliding contact in connection with this fixed contact arrangement.
Fig. 5 further represents the method of connecting the fixed contacts to the circuit
wires especially when of the concentric or armoured class. J is a metal box provided
with tubular projections K into which I solder the outer conductor of the concentric
wire on to which I have previously soldered a ferrule S which fits into the tubular
projections. I may however dispense with these ferrules. I sometimes provide an
insulating disc R in the bottom of this joint box. 1 unite the switch body to this
joint box by a screwed union P as shown and I carry the central wires O O through
this union into their respective contacts d d. When I apply my joint box to unite
lengths or branches of the concentric wires I modify it as in Fig. 7 which consists of
a metal box J. with a trunnion for each wire into which the outer conductor is
soldered and an insulating base I inside with grooves one for each wire and a central
recess to receive a metal contact m provided with grooves E into which to solder the
central conductors of the concentric conductor the insulation of which lies in the
grooves in the insulator, having thus made the connections I place in a insulativo disc
and then a metal disc which I solder into position. When I employ my joint box
for the connection of fittings provided with a spring contact such as is herein
described, I modify the box as shown in Fig. 8. The box is constructed similar to
that shown in Fig. 5. I construct a union D screwed into the box and I screw into
it the metal of the fitting which is provided with a spring contact that makes
connection with the metal contact m into which the circuit wire is connected. Fig. 9
represents a combined joint and switch box of which K are the trunnions into which
the outer conductors are soldered and the inner conductors are carried up and soldered
into the fixed contacts. Instead of uniting the fixed contacts by the spring contact
contrivance, I may connect them by a fuse wire in any known manner, preferably by
a separate plug G. of which W is the fuse wire.
Fig. 10 represents the connection of a flexible concentric conductor with a spring
contact terminal, F. is the ferrule soldered to the outer conductor by the reduced
part R.
C is the spring contact surrounded by an insulation I. I provide a union U
which turns freely on the ferrule, this union may have an outside screw instead of
inside as shown in the drawing.
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 :-
1. The spring plunger contact provided with central tube for effecting the soldering

page_text: 2. The spring plunger contact as described with reference to Fig. 3.
3. The construction of an electric switch with the fixed contacts with the
connection surfaces flush with the insulating material, as described in reference to
Fig. 4.
4. The modified construction of electric switch in which one contact is broader
than the other on which a spring contact slides when turned or oscillated and
breaks or makes contact with the other fixed contact as described in reference to
Fig. 6.
5. The construction of union boxes for connecting electric conductors having an
outer metallic envelope or conductor substantially as described with reference to
Figs. 5, 7, 8 and 9.
6. The construction of union for connection of flexible electric conductors and
electric fittings as described with reference to Fig. 10.
J. D. F. ANDREWS.