IMPROVEMENTS IN ELECTRICAL INTERRUPTORS
Year: 1881

page_text: LETTERS PATENT to Percy Ullathorne, of 323, High Holborn, London, in the
County of Middlesex, Electrician, for an Invention of "IMPROVEMENTS IN
ELECTRICAL INTERRUPTORS."
PROVISIONAL SPECIFICATION left by the said Percy Ullathorne at the
Office of the Commissioners of Patents on the 12th August 1881.
PERCY ULLATHORNE, of 323, High Holborn, London, in the County of Middlesex,
Electrician. "IMPROVEMENTS IN ELECTRICAL INTERRUPTORS."
This Invention relates to that class of instruments known as electrical current
interruptors, rheotomes, or contact breakers, and is applicable to the ordinary
purposes of telegraphy, duplex and multiplex telegraphy and telephony, to electric
lighting, and to some forms of musical instruments. It is capable of considerable
modification, but I will describe its main features and some of the more likely
modifications.
In its first form then it consists essentially of three stretched metal strings or
wires nearly parallel to each other, but not in the same plane. The contact wire
is platinized at its contact point, and must be insulated from the other two which
are suitably attached to the ends of a soft iron armature lying in the plane
between the contact wire and the two external wires, and the part thereof which
makes contact with the contact wire is platinized.
The wires are stretched over bridges which may be three or more in number,
and the armature may bisect the vibrating portion of each of the wires to which it
is attached, and these four vibrating sections may be equally stretched and of
equal length, density, and diameter. The contact wire is stretched upon bridges,
one of which may with advantage be placed very near the armature and may be
separated from the others.
An electro magnet is placed on that side of the armature which is farthest from
the contact wire. Supposing the current to enter the coil of the electro magnet, it
passes to the extremity or extremities of the armature wire or wires and into the
armature; from the armature it passes to the contact wire, and makes its exit from
Paine 621

page_text: one or both extremities of the vibrating portion of the contact wire which is not
furthest from the arinature. Some of the advantages of the above described
apparatus are that it admits of easy and very fine adjustment, the wires being
stretched over bridges which are mounted on screws or equivalent to allow of
their being moved in any required direction. The tension of the wires may be
easily altered and also the length of their vibrating portions.
Although the instrument as previously described has three wires, it may be made
with a greater or less number of wires, and the configuration of the armature
admitting of considerable variation. The instrument may even be constructed with
only one wire, for instead of the other wire may be employed a vibrating armature
consisting of a soft iron bar mounted at one end on a rather stiff steel spring,
something like the free reed of a harmonium; this should be platinized at the
point of contact with the wire, an electro magnet being placed on that side of it
which is farthest from the contact wire.
Another modification consists of a vibrating armature attached to a spring_at
each end at right angles or nearly so to its longer axis; these springs are by
preference secured between pairs of wedge-shaped wooden blocks, and the contact
point, which is preferably in the centre of its length, is platinized. A single wire
only is used in this case also.
In some cases a cone, bell sphere, cylinder tube, or other suitable attachment may
be fixed upon the contact wire or wires, and subject to certain precautions; one
or all of the vibrating wires may be attached by one extremity only to the rigid
part of the apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Percy Ullathorne in the Great Seal Patent Office on the
11th February 1882.
PERCY ULLATHORNE, of 323, High Holborn, London, in the County of Middlesex,
Electrician. "IMPROVEMENTS IN ELECTRICAL INTERRUPTORS."
This Invention relates to that class of instruments known as electrical current
interruptors, rheotomes, or contact breakers, and is applicable in cases where a
regularly intermittent current is required.
In its first form it consists essentially of three stretched strings or wires or
their equivalent nearly parallel to each other, but not in the same plane.
The contact or anvil wire may be platinized at its contact point, or may be made
of a suitable alloy as of platinum and iridium, and must be insulated from the
other two which are suitably attached to the ends of a soft iron armature lying in
a plane between the contact wire and the two external wires, and the part of the
armature which makes contact with the contact wire is platinized or otherwise
suitably protected.
The wires are stretched over bridges or their equivalent, and the armature inay
bisect the vibrating portion of each of the wires to which it is attached, and these
four vibrating sections may be equally stretched, and of equal length, density, and
diameter. The contact wire is stretched upon bridges, one of which may be placed
very near the armature and may be separated from the others.
An electro magnet is placed on that side of the armature which is furthest from
the contact wire. Supposing the current to enter the coil of the electro magnet, it
passes to the extremity or extremities of the armature wire or wires and into the
armature; from the armature it passes to the contact wire, and makes its exit from
one or both extremities of the vibrating portion of the contact wire. Some of the
advantages of the above described apparatus are that it admits of easy and very
fine adjustment, the wires being stretched over bridges which may be mounted on
screws or equivalent so as to allow of their being moved in any required direction.
The tensions of the wires may be easily altered and also the lengths of their
vibrating portions.
Although the instrument as previously described has three wires, it may be
mado with a greater or less number of wires, and the configuration of the armature
admits of considerable variation. The instrument may even be constructed with
only one wire, for instead of the other wires may be employed a vibrating
armature consisting of a soft iron bar mounted at one end on a rather stiff steel
spring; this should be platinized at the point of contact with the wire, an electro-
magnet being placed on that side of it which is furthest from the contact wire.
Another modification consists of a vibrating armature having a spring attached.
at each end and at right angles, or nearly so, to its longer axis; these springs are
by preference secured between pairs of wedge-shaped blocks of any suitable
material, and the contact point, which is preferably in the centre of its length; is
platinized. A single wire only is used in this case also.
Reference being had to the accompanying Drawings, in which like letters of
reference represent like parts,
Fig. 1 is a side elevation, and
Fig. 2, a plan of my Invention as carried out in its complete form with three
wires.
Figs. 3 and 4 are modifications in which one wire only is employed.
As shown in Figures 1 and 2 the instrument is suitable for the production of
a musical note, and to this end the framework may be made of wood, and hollow,

page_text: .
and provided with sound-boards to reinforce the note. This form is however
applicable to other purposes besides producing a musical note, and the sound-
boards can be omitted, and the frame-work need not necessarily be made of wood,
as other materials can be employed, due attention being of course paid to
insulation.
-
A is the base plate or stand; B, the sound board, shown divided in its length for
convenience of placing the electro magnet C; D is the armature attached to the
two external wires E, and F, the contact wire platinised at F and insulated where
necessary, as at F³, and secured to the wrest pins G, by which it can be strained to
the required pitch. The external or armature wires E are also attached to other
wrest pins G¹, but as stated the contact wire F is insulated from them.
In the Drawing the adjustment bridge H for adjusting the height of the contact
wire consists of a bent lever or bridge H, through the upper end of which passes
the wire F, the lever is as it were hinged at H, and by the nuts H², H³, and H*,
the end is tilted up and so raises the wire. The exact form of bridge is however
immaterial so long as the proper result is obtained; B¹ are bridges over which the
wires are stretched, and these are also adjustable.
In Figs. 1 and 2 a lever I is shown, by pressing which the contact wire may be
tightened and the note temporarily altered. Similar levers may, if desired, be
applied to the other wires.
The action is as follows:-The current by the wire 4 enters the coil of the
electro magnet C, passes by wires 5 and the binding screws and rods 6 and 7 to
the armature wires E through the armature D to the contact wire F, and so off by
the return wire 8. The normal position of the armature D when not in operation
is touching the contact wire at F (where both contact points are platinized), but
when the current vitalizes the electro-magnet C it attracts the armature D to itself
and away from the contact wire F, whereupon the circuit is broken, the armature
released, and the circuit established again immediately. This action continues as
long as the current is kept up, and with a suitable adjustment a musical note is
generated, the pitch of which, as already stated, can be varied by altering the
tension of the wires.
Figure 3 shows a simple interruptor and consists of a framework A carrying an
electromagnet C, contact wire F, and vibrating armature D, free at one end and
secured by a pliable connection, preferably a thin piece of steel, at the other, as is
clearly shown in the Drawing. The action is similar to that of Fig. 1. The current
by the wire 4 enters the coil of the electro magnet C, passes by wire 5 to the
fixed end of the armature D, from the end of the armature D it passes at F¹ to the
contact wire F and is led off by wire 7 which may be attached by the binding
screw 6.
In Figure 4 the stand or block A supports the vibrating armature D which is
platinized at D¹, where it makes contact with the contact wire F at F. At each
end of the armature, and at right angles or nearly so to its longer axis, is attached
a thin plate of steel K which admits of its vibrating. The current is led up to the
armature by wires 4, and the action is similar to that of Fig. 3.
It will be understood that modifications may be made in the form and arrange-
ment of these instruments, for instance, in Fig. 1 the electromagnet may be placed
above the wires instead of below, or a fourth wire may be introduced if desired
below the armature. Or if a mercurial contact be required a point or arm
depending from the armature would dip into a cup of mercury covered with fluid
to prevent sparking, as will be well understood. Also an extra wire may be placed
in such a manner as to close an independent circuit when desired.
As previously described the wires E both move together and in the same
direction, but this is not necessarily the case, as for instance, if one end of the
armature D (Fig. 1) be prolonged and the electro magnet applied towards that end,
a torsional or opposite movement will result to the wires, one being pressed up
and the other down. In practice, however, the armature may in such case (with.a
horizontal magnet or induction coil) be hung in a vertical position, the wires being

page_text: arranged one above the other, and there may be one or more contact wires arranged
so that one (for an independent circuit) is touched when the armature is attracted
to the electromagnet and another when it is withdrawn.
Having now described my Invention and the method of performing the same, I
wish it to be understood that what I claim and desire to protect under the herein-
before in part recited Letters Patent is,-
First. The combination of the vibrating wires E, to which is secured the
armature D with the contact wire F, substantially as and for the purposes set forth
and shown in Figs. 1 and 2 of the accompanying Drawings.
Second. The combination with a vibrating armature D of the stretched contact
wire F, substantially as and for the purposes set forth and shown.
Third. The employment of adjustable bridges or their equivalent, whereby the
positions of the wires can be adjusted, substantially as set forth and shown.
Fourth. The combination with the armature D of two or more stretched
wires E, to which said armature is attached, and by which its movements are
controlled, substantially as set forth and shown.
In witness whereof, I, the said Percy Ullathorne, have hereunto set my
hand and seal, this Ninth day of February, in the year of our Lord One
thousand eight hundred and eighty two.