Year: 1887

page_text: Date of Application, 12th July, 1887
Specification Accepted, 24th Feb., 1888
'
A communication from abroad by GEORGE WESTINGHOUSE, Junior, of Pittsburg,
County of Alleghany, State of Pennsylvania, United States of America,
Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S. M.I.M.E. of the Agency. for Foreign
Patent Solicitors 6, Lord Street Liverpool and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323 High Holborn in the County of Middlesex, Civil
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 :-
The invention relates to the class of apparatus employed for indicating the current
traversing any given circuit.
In the accompanying drawing Figure 1 is a front elevation of an apparatus
embodying the features of the invention, figure 2 is a plan of the same; figure 3
illustrates a modification. Figures 4, 5 and 6 illustrate the method of forming a soft-
iron core specially suited to the apparatus.
Referring to the figures, A represents an index hand moving over a scale B. This
hand is carried upon an axis a, carrying a pinion a'. This pinion gears with the
toothed segment c, carried upon an axis c¹.
An arm d', extending from the axis c¹, carries a core d, which is loosely suspended
within a coil D by a core d. A guide-rod serves to centre the core in the coil. The
coil D may with advantage be a convolute of sheet copper wound from a brass centre-
cylinder D. The convolutions are separated by an air space. This affords ventilation
and the largest possible radiating surface. This coil may be constructed of coarse
wire, but in either case it is capable of conveying all the current required upon the
line to which the instrument is applied, and it is included in the direct circuit of that
line.
An arm e, having an adjustable weight e¹, extends from the axis c¹, and acts as a
counterpoise for the core. By properly adjusting the weight upon the arm, the
change in the attraction exerted upon the core during its movement within the coil,
Price 1

page_text: may be compensated for by the change in the leverage through which the weight
acts.
In figures 1 and 2 the core is shown as suspended from an arm in such a manner
that variations in the position of the core, will occasion such variations in the leverage
as to partly compensate for the variations in the pull exerted by the coil. By properly
proportioning the lengths and the angles of the arms d¹ and e, the scale may be
graduated very evenly.
The usual watch-spring e³, may be employed for taking up the lost motion of the
gearing.
In figure 3 there is shown in place of the arm supporting the core, a curved
segment g, which carries the cord d² supporting the core and causes it to fall in a
direct line at all times.
The core is preferably made up of fine iron wires insulated from each other and
rolled in the form of a cylinder.
It has heretofore been proposed to form the cores of electro-magnets from compact
bundles of soft iron wires. For the purpose of the present invention, it is desirable
that such wires should be to a greater or less extent magnetically insulated from each
other, and also that the wires should lie as nearly parallel as possible.
This part of the invention therefore consists in general terms, in constructing the
cores in the following manner: H³ represents a hollow cylinder of paper or other
similar flexible, non-magnetic material. It is preferably carried by a cylindrical
block H. This may be made compressible like a chuck, or it may be grooved length-
wise to facilitate removing or cutting the sheet. The outer surface of the paper is
first coated with any suitable varnish, shellac or other suitable material, and the
wire His evenly wound upon it. The wire may itself be first covered with a
coating of shellac or varnish. The wire is of soft-iron and preferably of very small
size.
After the varnish or other coating has dried, the sheet is cut apart for example
along the line h h and flattened out, as shown in figure 5. The sheet or portions
thereof cut to the proper length and breadth, is then rolled up in the manner shown
in figure 6. This separates the wires slightly from each other, and the spaces thus
formed are preferably filled by the application of shellac or other equivalent material.
Usually it is found desirable to coat the sheet with a coating of adhesive material, for
which the shellac or varnish answers the purpose well, and this serves to bind the
convolutions together. The sheet may be wrapped on a non-conducting cylinder,
such as glass for instance, when it is desired to produce a hollow core.
A meter constructed in the manner described is applicable to electric systems
employing alternating electric currents, as well as to those employing continuous
currents. The core when formed in the manner described is susceptible of rapid
change in magnetic condition.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1st. An electric meter consisting of a movable core or armature, a coil included in
the main line, into which said core is drawn a greater or less distance according to
the attraction exerted upon the core, a support for said core, a toothed segment moved
by said support, an index hand geared to said segment and an adjustable counterpoise
for balancing the weight of said core, supported from the axis of said segment.
2nd. The combination of an indicating arm, a scale for the same, a movable core,
a coil included in the main line circuit and acting upon said core, a toothed segment
moved by said core, an adjustable counterpoise for the same supported from the axis
of said segment, an index geared to said segment and a watch spring applied to the
axis of said index for taking up the lost motion, substantially as described.
3rd. An electric meter for alternate electric currents, consisting of a magnetizing
coil, a core movable therein composed of magnetically separated soft-iron wire, and an
indicator operated by the movements of the core.

page_text: 4th. In an electric meter for alternating currents, the combination of a magnetizing
coil, a core moving therein, consisting of a convolute of non-conducting material,
covered by wires of soft-iron, and an indicator operated by the movements of the
core
5th. A core for electro magnetic apparatus for ammeters consisting of a convolute
of non conducting material covered by wires of soft iron.
6th. A core for electro-magnetic apparatus ammeters consisting of a sheet of paper
or other non-magnetic material, covered with soft iron wires and wrapped upon itself,
substantially as described.
7th. As an article of manufacture, a sheet of non-magnetic non-conducting material
covered upon one side by wires of soft iron, substantially as described.
8th. The herein before described method of forming cores for electro-magnets, for
ammeters which consists in winding wire upon a non-conducting sheet, cutting the
wires across their lengths and wrapping the sheet upon itself, substantially as set
forth.
WM. P. THOMPSON & Co.,
Agents for the Applicant.