Improvements in Electric Switches and Circuit Closing and Opening Devices.
Year: 1891

page_text: Date of Application, 28th Apr., 1891
Complete Specification Left, 20th Feb., 1892-Accepted, 28th July, 1392
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches and Circuit Closing and Opening
Devices.
'
GERALD PERCIVAL 30 Georges Street Cork Electrician do hereby declare the
nature of this invention to be as follows viz. :—
The use of inclined surfaces and non-inclined surfaces arranged so as to come
into action one after the other conjointly with contact piece brushes or surfaces
adapted to the said inclined or non-inclined surfaces, and capable of moving
relatively to them and of various means of imparting such motion and in some cases
of the arrainging of the various parts of the device that necessary contact between
the moving and the fixed surfaces is maintained by the action of gravity or gravity
in conjunction with springs.
By inclined surfaces I mean surfaces which in moving cause motion in another
direction in parts or surfaces resting on them or such that on the parts in contact
with them being moved these parts receive an additional motion due to their
contact with the surfaces on which they rest, and by non inclined surfaces I mean
surfaces which do not cause any such motions or only such sleight motions as may
be due to the imperfection of such surfaces. The inclined surfaces may take the
form of the sloping side of a wedge, or the slopeing side of a ratchet tooth in a
ratchet wheel, or part of the surface of a circle or cylinder whos axis is excentric
to the axis of motion. The non inclined surfaces may be either plain surfaces
parallel to the direction of motion, or parts of circles or cylinders, or cones whos
axis coincide with the axis of motion, in making a switch, or circuit closing or
opening device I use at least two surfaces one inclined and one non inclined but not
always an equal number of each I so place the surfaces that one end of the inclined
surface is above the level of the non inclined surface or surfaces, and the other end
below the level. When the apparatus is intended for continuous use I arrange the
series of inclined and non-inclined surface in the form of a toothed wheel of at
least two teeth, and when the circuit is to be broken at more than one point at the
same time of at least three teeth one at least of the teeth being an inclined one.
I in some forms of my invention intended to be of low resistance, make the acting
faces of the non-inclined surfaces or teeth parts of a cone whos axis is coincident
with the axis of motion, and I form the parts intended to move on such conical
non inclined acting faces in many cases of a number of thin plates of metal
of differing lengths so placed one over the other that they together present a
conical surface, by preference a somewhat more obtuse cone than that on which
they are to rest, the whole apparatus being so constructed that sufficient pressure is
brought to bear on these plates and they are somewhat deflected from their
normal form so that each individual plate has an indipendant bearing, such plates
being approximately straight or flat, the motion when in contact with the conical
non-inclined surfaces being parellel to the plane of such plates of metal.
I sometimes make the non-inclined, and inclined surfaces at different distances
from the axis, so that though they come into action one after the other they at'no'
part touch one another.
For actuating these switches I provide either a knob or lever handle usually
oosely attached to the moving part to permit it to fall freely from one surface on
o the other or I provide them with one or more electro-magnets or solenoids and
utable armatures or magnets which they can attract and which are attached to
'

page_text: the moving part, the coils of the electro-magnets or solenoids being either shunts
to in series with or on a separate circuit, according to circumstances.
Dated this 27th day of April 1891
GERALD PERCIVAL,
30, Georges Street, Cork, Electrician.
COMPLETE SPECIFICATION.
Improvements in Electric Switches and Circuit Closing and Opening
Devices.
GERALD PERCIVAL 30 Georges Street, Cork, Electrician 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 :-
My invention consists of the use of inclined surfaces & non-inclined surfaces
arranged so as to come into action one after the other, conjointly with contact
pieces brushes or surfaces adapted to the said inclined or non-inclined surfaces and
capable of moving relatively to them and of various means of imparting such
motion and in some cases of the arranging of the various parts of the device that
the necessary contact between the moving and fixed surfaces is maintained by the
action of gravity or gravity in conjunction with springs.
By inclined surfaces I mean surfaces which in moving cause motion in another
direction in parts or surfaces resting on them, or such that on the parts in contact
with them being moved these parts receive an additional motion due to their contact
with the surfaces on which they rest; and by non-inclined surfaces I mean surfaces
which do not cause any such motions, or only such slight motions, as may be due to
the imperfection of such surfaces. The inclined surfaces may take the form of the
sloping side of a wedge, or the sloping side of a ratchet tooth in a ratchet-wheel,
or part of the surface of a circle or cylinder whose axis is eccentric to the axis of
motion. The non-inclined surfaces may be either plain surfaces parallel to the
direction of motion, or parts of circles or cylinders or cones whose axis coincide
with the axis of motion. In making a switch or circuit closing or opening device
I use at least two surfaces, one inclined and one non-inclined but not always an
equal number of each, I so place the surfaces that one end of the inclined surfaces
is above the level of the non-inclined surface or surfaces and the other end below
the level. When the apparatus is intended for continuous use, I arrange the series
of inclined and non-inclined surfaces in the form of a toothed wheel of at least
two teeth and when the circuit is to be broken at more than one point at the same
time of at least three teeth one at least of the teeth being an inclined one.
I in some forms of my invention intended to be of low resistance, make the
acting faces of the non-inclined surfaces or teeth parts of a cone whose axis is
coincident with the axis of motion and I form the parts intended to move on such
conical non-inclined acting faces in many cases of a number of thin plates of metal
of differing lengths so placed one over the other that they together present a conical
surface, by preference a somewhat more obtuse cone than that on which they are
to rest, the whole apparatus being so constructed that sufficient pressure is brought
to bear on these plates and they are somewhat deflected from their normal form so
that each individual plate has an independant bearing such plates being approxi-
mately straight or flat, the motion when in contact with the conical non-inclined
surfaces being parallel to the plane of such plates of metal.
I sometimes make the non-inclined and inclined surfaces at different distances
from the axis so that though they come into action one after the other, at no part
touch one another. For actuating these switches I provide either a knob or lever
handle usually loosely attached to the moving part, to permit it to fall freely
from one surface to the other, or I provide them with one or more electro magnets
or solenoids and suitable armatures or magnets, which they can attract, and which
are attached to the moving part, the coils of the electro magnets or solenoids being

page_text: "
either shunts to, in series with, or on a separate circuit.according to circumstances,
which are determind by when the motion is desired to take place, if it is to be
when the electromotive force or difference of potential of two points exceeds a
certain predetermind amount, then coils will be placed as a shunt to these points,
if however it is desired that the apparatus is to act as what is known as a "cut
out on the current passing between any two points exceeding a certain pre-
determined numbers of amperes or parts of an ampere then the coils will be in
series with these two points and convey the current or part of the current passing
between them, or if the predetermind condition is that only a certain number of
"Watts," shall pass through the device then a combination of both windings can be
used. Or the winding may be connected by conductors to a distant point from
which the current for actuating the switch can be sent.
The arrangement of the magnetic parts for moving the switch speaking generally
take the form of a peice of soft iron or a peice of magnetised steel or cast iron
attached to the moving part, so that the two ends or poles of such peice of iron or
steel project at each side of the axis of such moving part, and of a fixed electro
magnet of soft iron or steel core wound with insulated wire of sufficient size &
number of turns to convey the current to be used to magnetise it and so placed that.
when the switch is "on "
or has closed the circuit on which it is designed to act,
the poles of such electro magnet are a few degrees of arc in advance of the position
occupied by the ends of the iron on the moveable portion, and near enough to them
to attract them, so that when the current passes through the wire and energises the
electro-magnet the tendancy will be to drag round the moveable portion and as
soon as the force so exerted becomes greater than the friction and resistance to be
overcome the motion so caused will turn the switch far enough to cause the switch
to move to the off position and so break circuit. A similar device may be used to
move the switch to the "closed circuit" or "on" position, but must be stronger
as the parts have to be in this case moved against the action of the inclined
surfaces.
I construct the apparatus in such a manner that, on the conducting part which
makes contact with the non-inclined conducting surface when the switch is closed,
leaving or falling off from such surface it has sufficient room to fall to such a
distance as may ensure complete and instantaneous breaking of the arc which is
formed when two conductors between which a current is flowing are separated and
this distance I determine by experiment with two peices of the kind of conductor
which is to be used in the manufacture of the surface of the non-inclined surface of
the switch or device, and the part which is to make contact with it using in such
experimental determination a current and electromotive force similar to that with
which the switch is to work causing such current to traverse such peices of
conductor in contact with one another, and then, separating them slowly so as to
cause the arc to extend between them, continuing the motion until the arc breaks
such distance is the least which must exist between the conducting parts of the
switch or circuit opening & closing device when they separate.
To insure the separation taking place I either form the moving portion of
sufficient weight to fall by gravity of its self or apply a weighted lever to press the
moving part in contact with the conducting surface or surfaces which pressure
causes the moving part to fall free of the part on which it has been resting as soon
as its motion carries it beyond the end of such part, the use of heavy parts or
weighted levers to cause the necessary pressure between the parts and their quick
motion away from one another when they separate is particularly suitable to switches
of great size or designed for use in places where corrosive or acid vapours would
be likely to injure springs such as in accumulator rooms etc., I also use a spring or
springs when the switch is of small size or when it is to be used in ordinary
positions these I apply in such a manner as to insure the necessary pressure between
the contact surfaces and their subsequent rapid separation when they leave one.
another.

page_text: In the accompanying drawings
Fig. 1. Sheet 1. is a form of my invention in which C. C. are two inclined
surfaces & A. A. two non-inclined surfaces these latter are faced with metal shown
white in the drawing the main portion or body F. is formed of an insulating material
and the inclined surfaces are formed on it as shown at C. C. this portion or body is
shown in plan and elevation. The portion lettered H is the moving part and
consists of a round plug of insulating material having an internal chamber containing
a spiral spring shown by a dotted spiral e. the plug has a slot formed in it parallel
to its axis and extending completely through from side to side in this slot the part
lettered B. which is of metal can move freely up and down, being pressed downwards
by the spiral spring in the chamber as shown by the dotted lines. The plug is made of
such size as to fit freely into the circle in the base part F. formed by the inclined
surfaces C. and the non-inclined surfaces A. The circle enclosed by these being
sunk sufficiently deep into the base F. to admit the plug some distance below the
lowest part of the inclined surfaces to give greater bearing and steadiness the
plug His shown lifted out of the base for the purpose of clearer representation and
the containing case or cover of the device is only shown by a dotted line g. as its
form would mainly depend on the amount of exterior ornamentation deemed
advisable in any instance, when the plug H. is inserted in the base F. and then
turned round its axis the metal bar B. B. will be in contact with either the inclined
or non inclined surfaces and if rotated in the direction in which these inclines rise
it will while passing over them cause the metal bar B. B. to rise in the slot in the
plug and in so doing compress the spiral spring until the highest parts of the
inclines are passed when the spring will react and force it down on to the non-
inclined surfaces these are faced with metal and are the portions attached to the
electric circuit on which the device is to work and when this action takes place
these two surfaces will be joined by the conducting bar B. B. and the circuit closed.
When the plug H is rotated further the bar B. B. will fall from the non-inclined
surfaces A. A. into the lower part of the inclined surfaces C. C. and the circuit will
be broken.
Fig. 2 Sheet 1 is another form in which the inclined & non inclined surfaces are
the moving part, the non inclined surfaces are lettered A. A as before & the inclinel
ones C. C., these four surfaces form a sort of ratchet wheel and can turn freely on
the central pin K. On opposite sides of the axis two pawls or detents B. B. are
pressed against the wheel by springs e. e. and are the conductors which by falling
on the surfaces A. A. close the circuit or by falling off on to the surfaces C. C.
break circuit in the particular case shown these pawls are made of metal cases filled
with strips of wire gauze J. J. fixed at one end to the metal parts D. D. being
curved round the pins M. M. on which the pawls turn so as to have sufficient
flexibility to allow these pawls to move, the whole of these parts are mounted &
attached to the base F. in any convenient manuer and a knob or handle which
may take the form shown by dotted lines at H is provided with a recess in its
underside which encloses loosely the pin L. by which motion can be imparted to
the ratchet wheel in both Figs. 1 & 2 Sheet 1. the portions ruled with horizontal
lines are insulating material which remains fixed and the parts ruled with diagonal
lines are insulating portions which move when the device is actuated, the metal
or conducting parts are left white or unruled.
Fig. 3 Sheet 2. is a form of the device in which the inclined surfaces C. C. non-
inclined surfaces A. A. are at different distances from the axis and in which the
non-inclined surfaces A. A. are shaped to part of a cone, and the contact bar B. B.
is made up of a number of thin plates of metal with their ends projecting one
over the other so as to form a conical surface suitable to rest on the surfaces A. A.
and make good contact with them. On the upper side of these a longer peice of
metal N, is fixed so formed that it is free of the surfaces A. A. and projects beyond
them, and when the part B. B. falls off from the surfaces A. A. it descends until
the ends of N. rest on the lower part of the inclined surfaces C. C. the action being

page_text: similar to the form shown at Fig. 1. Sheet 1., but instead of a simple knob or
handle for moving this portion a magnetic arrangment is shown on the upper part
of the figure which consists of an iron armature or magnet P. and a ring shaped
electro-magnet R. with two projecting pole pieces S so placed that they tend to.
pull the armature or magnet P. round in the direction to cause the contact bar B. B.
to fall off from A A this ring shaped magnet may be made adjustable by fixing
its relation to the other parts of the apparatus by clamping screws instead of simple
pillar supports as shown at T. a few turns of the wire for energising the ring.
magnet are shown at U but usually the whole ring except the pole peices would be
covered.
In each fig. the lower part is a plan and the upper part an elevation of the same.
apparatus, in Fig. 3 Sheet 2 the elevation is a section through the middle of the
non-inclined surfaces & axis.
No special terminals are shown in any of the drawings as any of the ordinary
forms may be used.
No handle is shown in Fig. 3 as the armature P serves the purpose but a handle-
can be fixed to it if desired.
The drawings are in proportion but not to any particular scale as size would
depend on the use the apparatus was to be put to.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is
1. In a circuit closing & opening device the use of non-inclined & inclined
surfaces, used in conjunction and arranged substantialy as set forth.
2. The so arranging & constructing the parts in substantialy the same manner-
described to insure a complete and sufficient breaking of the circuit.
3. The use in some cases of gravity as means of causing the necessary contact
& falling of the parts in such device substantialy as described.
4. The use in conjunction with such device of conducting contact surfaces for
the non-inclined surfaces turned or formed conical or the shape of part of a cone.
5. The use in such device in conjunction with such surfaces of contact peices
composed of thin plates of metal used substantialy as described.
6. The use in conjunction with such device of electro magnets or solenoids
applied & used substantialy as described, and
7. The arranging of the non-inclined & inclined surfaces in the form of a toothed
wheel one after another but not necessarily at the same distance from the axis of
motion.
Dated this 18th day of February 1692.
1092.
GERALD PERCIVAL,
30, Georges Street, Cork, Electrician.