A BI-POLAR SWITCH FOR ELECTRICAL CURRENTS
Year: 1885

page_text: We ROBERT MAJOR BAILY Junior Engineer and ALFRED GRUNDY Electrician
both of Amberley Works Amberley Road Paddington Middlesex do hereby declare
the nature of our invention for A BI-POLAR SWITCH FOR ELECTRICAL CURRENTS
to be as follows:―
3 Conveniently fixed to a block of wood or other suitable material, are four
terminals with suitable binding screws these terminals are two on either side and
all insulated from each other, to each of these terminal posts is secured an arm
of metal terminating in a block of metal with a faced surface so arranged that
the faced surfaces of the arm from each terminal comes opposite to the faced surface
of the arm of the terminal immediately opposite to it The inner two of these
arms may be of flexible material but of sufficient stability to carry the maximun
current for which the switch is designed without heating.
The blocks of the outer arms may be rigidly fixed or the arms may be made
flexible as convenient or desired.
Pivotted in the centre of the base block and evenly between the metal blocks of
the arms is a block of insulating material of an oval or oblong shape and provided
with a suitable handle for turning the same.
The poles of the generator being connected to two contiguous terminals and the
line wire to the two opposite ones, on turning the handle until the length of the
block lies, between the metal blocks of the inner arms the said arms will be
simultaneously forced outwards and contact made between the faced surfaces of the
blocks while when the breadth only of the block lies between them they are at
liberty to separate and the contact is broken at both points also simultaneously
should the break not be rapid enough it may be supplemented by means of suitable
springs.
The movable centre block may if desired be provided with suitable spring or
other arrangements for holding it firmly in the " on" or off" position.
..…
1

page_text: An improved Switch for Electrical Currents.
We ROBERT MAJOR BAILY Junior Engineer and ALFRED GRUNDY Electrician
both of Amberley Works Amberley Road Paddington Middlesex 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 :-
The object of this invention is the construction of a Bi-polar switch which will
simultaneously and instantaneously make or break two or more points in both the
positive and negative wires or leads of an clectrical circuit without the drawback
of sparking which happens whenever currents of high tension or great quantity
are being manipulated.
The invention will be readily understood by reference to the accompanying
drawings on which letters of reference are marked on corresponding parts on all
figures alike.
Fig. 1 represents a plan view of the Bi-polar switch in which a handle is
employed for making or breaking the electric circuits.
Fig. 2. is a side elevation of the same.
Figs. 3 and 4 represent respectively a side elevation and plan of the same switch
in which the movement of the contact making parts is effected by means of toothed
segment and rack.
Fig. 5 is a detached side elevation of one of the contact making parts and one
terminal shewn in position with the circuit made or closed.
In these figures a is the base plate of wood or other insulating material to which
are attached the four terminals or binding posts bbc c¹ provided with suitable
clamping screws or connections for the conductors. These terminals are placed in
pairs and are provided with contact points as under.
To the terminals bare secured flexible arms of metal f f terminating in blocks
of metal e¹ e'.
The terminals c c¹ are provided also with springs d carrying the blocks e e and
each pair of blocks e and e¹ are adjusted exactly opposite to each other and their
inner surfaces faced to ensure good electrical contact These arms and blocks must
be of sufficient conductive capacity to carry the current for which the instrument
is designed or intended without heating.
Mounted on an axis and working in the bearings ii are the discs g g' which
may be round oval or of an oblong shape the periphery of these discs are adapted
to and fit eveuly between the inner faced surfaces of the blocks e e'.
The poles of the generator being connected to the two contiguous terminals b b²
and the line wires to c c' the action of the switch will be as follows:-—
Passing through the centre of the discs g g' are metal parts g2 the ends of which
are made the same size as and fitting evenly between the blocks eel when the
handle. Fig. 2 is forced down into a position paralell with the base board as
shewn in dotted lines the handle being held in that position against the strength
of the springs m. m. by the spring and catch n n¹ and the circuit between b & c is
completed at the two points e e¹ the same result is also obtained between b¹ & c¹.

page_text: On releasing the spring catch n the springs m m cause the handle k and the
discs g. 9 to rapidly revolve through a quarter of a circle the faced surfaces of e e¹
now rest on g³ which is an insulating material and consequently the contact
between e and e¹ is broken simultaneously in both the branches b c and b₁ c¹ The
handle k is of wood or some other non conductor so as to form a safe insulation
between the posts c c¹ and the axis ii is in two pieces each part terminating at the
junction with the handle.
As before stated the discs g may be of any suitable form so long as the metal
part g extends to the full diameter or breadth of them and are properly fitted and
faced to the blocks e. e¹.
Another method of rotating these discs is shewn in Figs. 3 and 4 where a rack. r
is pulled out by a knob k until the spring n drops into the hole o and by means
of the toothed quadrant revolves the discs through the necessary distance for
making contact. On releasing the catch n the spring m rapidly pulls back the bar
and rack and switches off in the same manner.
Any suitable device can be used in lieu of either of the foregoing so long as they
can be made to revolve the discs through the necessary quarter of a circle rapidly
and simultaneously.
Although the drawings illustrate a Bipolar switch with four terminals yet it will
be evident that by duplicating the parts b. c. e. and g. and connecting the leading
wires in continued series through them and all the discs corresponding to g being
coupled on to the same spindle the number of points at which the circuit can be
broken may be indefinitely multiplied so as to ensure the safe breaking of any
electrical circuit no matter of what tension without sparking or danger to the
operator.
Or again the switch in its form as shewn may if desired be used in single series
so as to break four points in one electrode instead of two each in both electrodes
Or the two branches b. c. and b₁ c¹ may be used for separate circuits if desired.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that what
we claim is
1st. In the construction of an electrical switch the combination of the discs or
blocks partly of insulating and partly of conducting material mounted on a spindle
or axis and making a breaking contact with the surfaces of the blocks e e¹ substan-
tially in the manner set forth and described herein.
"
'
2nd. The combination and rotation of two or more of these parts so as to form a
Bi-polar or single line switch as convenient or desired substantially. as described.
3rd. The combination of spring and catch as described for holding the switch in
the "
position with the method of releasing the same and breaking the number
of points required in the circuit with great rapidity and simultaneousness.
4th. The improvements in switches for electrical currents substantially as herein
set forth and described.