Electric Meter.
Year: 1899

page_text: Date of Application, 17th June, 1899-Accepted, 2nd Sept., 1899
Electric Meter.
I, EDWARD S. HALSEY, residing at 1022, Benson Avenue, in the City of Evanston,
County of Cook and State of Illinois, U.S.A., and by calling am an 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 relates to a recording electric current meter of a mercury motor
type, and the objects of my invention are:-
First: To make a meter of wider range for a given capacity and of greatest
accuracy throughout its extreme range.
Second: To make it of very few parts, thereby reducing the manufacturing
expense and liability to disorder.
Third: Convenience of handling and operating; with compactness and lightness.
My invention consists of a set of wheel train counters, driven by a small
motor through which the curent to be measured passes, of a definite part thereof,
and the speed of rotation of said motor is in direct keeping with the amount
of current passing through it. The motor consists of a constant magnetic field,
preferably that of a permanent magnet, in this field rotates an armature consist-
ing of a continuous piece of copper about 16 inch in thickness and carried by
a vertical shaft which is geared through a worm, to the recording mechanism
at its upper end; but a small part of the armature lies within the magnetic field
at one time; the current is led to the armature by two small electrodes that dip
into the mercury in which the armature is submerged, at opposite borders
of the field so that the current will have to travel the whole length of the
field.
In the accompanying drawing, which illustrates my invention, similar numerals
refer to similar parts through the several views: Figure (1) is a view of com-
pleted meter with cover removed; Figure (2) is a sectional view through center
from the same position as in Figure (1); Figure (3) is another section of the
same, looking down from the top; Figure (4) shows the two pole-pieces. being
iron castings to be moulded into the composition body of the meter; Figure (5) is
a sectional view of the back-board and cover looking at it sidewise; Figure 6 is
is a sectional view of a small fraction of the lower part of the backboard and
cover from the front showing the cover-latch applied; Figure (7) is a sectional
and partial perspective view of another design of a meter introduced to illustrato
how some of the principles of my invention can be applied to different forms;
Figure (8) shows an edgewise view of a differential gear forming a part of the
recording mechanism; Figure (9) gives an introspection of the relative positions
and workings of the essential parts of the gear referred to from the front side.
Having briefly, described my invention I now proceed to describe it in full.
The construction of my meter will best be understood from the sectional views
(Figures 2 and 3) and consists mainly of three parts.
First: The permanent magnet (1) forming a strong field in the narrow gap
between its pole-piece (4) and (5).
י

page_text: Second: The armature consisting of a copper cylinder (2) 2¼ inches in
diameter and about twice its diameter in length and about 1/16 inches in thickness;
this armature is carried by a vertical steel shaft (9) through the medium of the
spider (14), shown as a transparency by dotted lines in Figure (3) which is
adjusted to shaft by the hexagon nuts (15); the armature is adjusted in its
bearings to rotate freely between the pole-pieces, in the magnetic field; it is
wholly submerged in mercury which is contained in a circular slot in the third
prominent part (3) which is the main body of the meter and acts as a receptacle
for the mercury and armature.
The aforesaid slot is of uniform width only sufficient for the armature to revolve
freely.
The inside pole-piece (4) and the outside pole-piece (5) present convex and
concave surfaces respectively to the walls of the slot of which they form a part,
'being treated with an insulating surface. The body or cup (3) is pressed out of a
mass of insulating material and into it are formed the pole-pieces and the two
copper electrodes (22) and (22); the pole-pieces each present a flat surface of
considerable area to the magnet, and have at the centers of said surfaces, screw
holes for means of securing them to the magnet which in turn is clamped to the
back-board. The pole-pieces being thoroughly embedded in the mass of body,
give to it sufficient rigidity.
The hole is
Straight through the axis of the cylindrical body is hole (12), at the bottom
it passes through the foot of pole-piece (4) and is tapped out for the anchor screw
which holds it to the magnet. This hole is a pit for the bottom
bearing (26) which is screwed into place from the bottom.
large enough for the shaft to turn freely and is filled with mercury.
The top of the receptacle is fitted with a cover (6) of composition having an
opening at its center in the form of a neck threaded on the outside, out of which
passes the shaft which carries a ballast weight (7) having a threaded cavity on its
under side, fitted with a rubber gasket (8), the weight is adjustable on the shaft
so as to be lowered and screwed on to the neck of the cover clamping the gasket
and thereby making the receptacle mercury tight and locking the meter so as to
stand transportation.
The main function of ballast weight is to compensate the buoyancy of the
copper armature floating in the mercury which is of greater specific gravity.
The top of shaft is fitted with a worm to engage a gear wheel (10) contained in
recording mechanism. The magnet surrounds and encloses the other parts
thereby making the whole arrangement very compact and also acts as a frame for
supporting the top bearing and recording mechanism.
: The cavity within the composition body is shaped to resemble the armature and
fitted as close as is consistent with the free rotation of same, thereby leaving as
little idle space as possible to be filled up with mercury.
The positive and negative electrodes (22) and (22) are of copper and present
to the mercury as small an area as is consistent with the required conductivity,
and are centrally located close to the end of the outer pole-piece (5) and are
embedded in the composition of body and lead out through its walls at convenient
points for connection with conductors (23) and (23) (the one from the top passing
behind body) which lead to the meter binding posts (13) and (13), shown in
Figure (1).
It is to be understood that the chamber of body is completely filled with
mercury well up into the neck, and that the current to be measured is led from
one electrode across a very short distance by the mercury to one extremity of the
armature through which the greater part of the current passes directly through
the center of the constant concentrated and powerful field; passing out through
the mercury and the other electrode at the other end. The pole-pieces are narrow
at the ends and wider in the middle to take in a greater number of current lines
which naturally diverge toward the center as they pass from one electrode to
another. Since the conductivity of the copper armature is nearly one hundred

page_text: times greater than that of the mercury it is obvious that the greater and a definite
part of the current will pass through the armature.
The chief characteristics of my invention and meter are three :-
First: The peculiar nature of the magnetic field:
Second The cylinder armature with a length considerably greater than its
diameter:
Third: The electrodes (22) and (22) limited to a small spot, and their respective
relations to other parts. One of the peculiarities of my meters is the fact that if
the field through which the current is, passed be weakened the speed will increase,
with the reversed effect if strengthened.
I effect a regulation of my meter by means of a shunt (19) being connected by
screws to the armature leads (23 & 23) having means of regulating its conductivity
by the sliding jumper (20).
In the smallest size this shunt will have its resistance proportionated so as to
take from the armature only; sufficient current to affect the desired correction
but in the larger sizes may have a conductivity sufficient to take a large and
definite part of the current to be measured thereby increasing the capacity of the
meter according to the size of shunt, but I prefer to accomplish increased meter
capacity by using a conductor of low resistance to be concealed in back of meter
(but is not shown) and connected in shunt with armature circuit and small
regulating shunt.
The third sheet of drawings is a diagram presenting the characteristic curves
of three different meters each being respectively marked on the diagram so as to
be easily distinguished from the others.
The first is the curved line described by my perfected meter with cylinder
armature as shown in the accompanying drawing.
The column of figures from top to bottom of diagram give the per cent. fast or
slow, from the starting point to point of full load as shown by the ampere scale
at bottom of diagram.
Although my meter will run constantly on 1/20 part of an ampere it runs so
slowly and ununiformly I have not attempted to show it, at the same time it is
obvious that it is impossible for it to run on no load; as will be seen from
diagram it has not an extreme error at 10 of an ampere and constantly improves
until at 2 ampere it is correct, and continues to rise until at about 1, load it
is one per cent. fast, from here it declines until at about 1, load it again becomes
correct, and still further it drops to one per cent. slow at its limit.
Another of the curves shown is that of a recording Watt-meter, this being the
only class of motor meters in common use in America, for the sale of direct
current electricity, it being obvious that this is the class of work my meter is
intended for, and one of the main objects of my invention being to make a meter
more accurate throughout its load and especially at very small loads without
danger of running on no load, I think it proper to present a comparison of the
results of my own with that of those now in common use.
Finally upon careful verification I think my curve comparisons herewith given
will be found very reasonable and impartial, and further that in carrying out
my invention I have produced a meter giving decidedly better results than any
now in use for this class of work.
For the purpose of showing the deterring influence of mercury contended with
and to give some idea of how large a part of the drag it constituted, I have
introduced a curve described by one of the meters over which I labored in my
early experiments; the armature was the disk type and the field was of a con-
siderable strength, sufficient to make the armature revolve with certainty on 1/10 of
an ampere; although the field was arranged to give a drag effect, still it was not
of sufficient strength and not concentrated or arranged so as to get its maximum
drag effect in which case it could have been made to show a great deal more
consistant curve, than the one shown on the diagram with an extreme variation
of 60%. In the second sheet of drawing Figure (7) is a sectional and partial

page_text: perspective view of a mercury meter with a copper disc armature (2) showing its
section through the center being supported by a vertical shaft (9) revolving on
point bearings, the disc revolving in a thin circular chamber with only sufficient
room for it to move freely and the surrounding space filled with mercury up into
the neck opening, left in the lid (6) for the introduction of the shaft; said lid or
cover of insulating material also having embedded and passing through it the two
magnet extremities or pole pieces (N) and (S), also the upper electrode (22)
centrally located so as to make connection by the disk and mercury through the
heart of the field, to the other electrode (22) entering by the side.
The bottom in form is an insulating plate having embedded in it a strip of soft
iron extending across its center serving to complete the magnetic circuit leading
from one pole to the other...
The circular top and bottom parts are bound and held together by a band of
insulating material (28) forming the outer wall for the mercury chamber:
The shaft carries the ballast weight (7) performing the same duty as in
Figure (1) and clamped to shaft by the thumb screw (25).
f
Figure (5) shows a sectional view looking from one side of back board (17);
cleats (18) and (18) acting at once as stiffness for back board, support for meter
and back stops for cover (29). There are four anchor bolts (16) fitted at one end
with a nut and at the other end with a claw for grasping the magnet to which all
other parts are fastened, and clamping it to the back-board. The cover (29)
completely envelopes all sides, except the back, and is fitted with window (30) at
the registering dial, and has a small round hole (32) at the bottom to fit the
bolt (21) and is re-enforced by a small metal plate at that point with a hole of
the same size. The bolt (21) is in a hole bored in the center of bottom of back
board in which it moves freely and may fall of its own weight as shown in
Fig. (6) or may be pushed by a small coil spring placed in the hole back, of it.
The lower section of bolt is cut down to a smaller size thereby making a
shoulder which rests against plate (31) with a hole in its center and acts as a
retaining stop for bolt and is counter-sunk in bottom of board and held by two
screws. The lower end of bolt is conical in shape to facilitate its passage through
the holes. In the bottom extremity of bolt is drilled a small hole for the intro-
duction of a seal wire as shows in Fig. (6).
;
The cover is adopted to back board by an overhanging edge at top of cover,
being lowered until it engages the top of back board, then the bottom of cover
is pushed back until its sides strike the ends of the cleats, when the bolt which
has simultaneously been lifted by the finger will drop into place through the
hole in the cover and is thereby latched ready for sealing.
It at once becomes apparent that the direction of rotation of my meter depends
on the polarity of the current introduced and upon the direction in which it is
carried through it, but in my case the meter would give a uniform result.
Therefore, to obviate the necessity of the workmen testing the wires for polarity
and service and further to guard against all possible harm from the reversal
of the polarity I have invented the differential gear, shown in Figures (8) and (9)
which is so constructed as to drive the ratchet wheel (33) and in turn the recorders
which are not shown but are to be geared to it in a forward direction regardless
of the direction taken by armature and intermediate parts.
On both sides of ratchet wheel are similar spurr wheels (37) and (38) each
having a similar_pall (34) and (34) so arranged as to become engaged with the
ratchet wheel. Both spurr wheels run loose on the shaft to which the ratchet
wheel is fixed and one is always driven in the opposite direction from the other,
the one taking the forward direction engaging the ratchet wheel by means
of its pall and driving it and the attached recorders always forward, while the
other spurr wheel runs in the opposite direction dragging its pall idly over
the ratchets.
The spurr wheels (37) and (38) are driven in the directions opposite to one
another by means of the pinion wheels (35) and (36) with which they are

page_text: "
respectively meshed. Pinion wheel (35) being fixed to the shaft of worm wheel (10),
must travel in the direction determined thereby, and being also meshed with,
pinion wheel (36) must develop therein a direction opposite to its own.
.
It is obvious that this gear could be differently constructed without altering the,
effect of the invention, for instance, instead of the common ratchet wheel each
pall might be fitted to an independent ratchet wheel. I am aware that there
have been mercury meters in use for some time in which the mercury itself acts.
as the armature and in which there is no magnetic drag, a consistency of rotation
being effected by means of an increasing field produced by series of windings.
I am aware that since I have labored with this invention another has invented.
a meter with a supplementary drag disc and a decreasing drag field by means of
series windings. I am also aware that others have attempted to construct a
practical meter with a cup armature and an enormous permanent magnet field,
the currents being fed at the center of bowl of cup and taken away at all points.
of the brim.
I am not aware, however, that any attempts have been made to use a
cylindrical armature of a considerable length or a concentrated elongated magnetic
field, with the current led in by small electrodes centrally located at both ends of
the pole piece, or of a general similar construction, to the one shown and claimed.
by me.
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-
First: In a mercurial electric current meter; a body of non-magnetic
material containing the mercury and armature, and having moulded or formed
into its walls pole-pieces (N) & (S) in combination with a constant, concentrated
and powerful magnetic field so proportioned and applied as to determine to the
armature a speed of rotation practically in direct proportion to the current
passing at various loads, in spite of deterring influences of the mercury and
unavoidable friction, regardless of any compensating device or influence; sub-
stantially as shown and specified.
Second-The. combination in a mercurial electric current meter: a mercury
chamber being a narrow slot in a body made of non-magnetic material, in greater
part magnetic poles (N) and (S) entering, to said chamber by its walls being
fixed. therein and defining thereby a magnetic field in said slot of small area
compared to the area of the chamber of which it is a part; electrodes (22)
and (22) entering to said chamber through its walls by which they
are held in position, being one at each end of said field centrally located
thereto and of small area so as to direct the current between said poles and
through the center of said field: an armature of sheet metal adopted to fit said
chamber in which it rotates submerged in mercury and is propelled by the
current led to it by said electrodes and is retarded by the magnetic field in which
it rotates, substantially as shown and specified.
Third: In a mercurial electric current meter pole pieces presenting to each
other surfaces widest at their centers and tapering toward the ends so as to
establish in the slot between them a magnetic field broadest at the center and
narrowing toward the ends; said pole pieces being of small area compared to
armature (2) rotating between them and small electrodes centrally located at each
end of said pole pieces as shown and for the purpose specified.
Fourth In a mercurial electric current meter a body or receptacle containing
and enveloping the submerged rotating armature and being formed or pressed
form non-magnetic material embracing, and holding in their fixed positions the
magnetic pole pieces (S) and (N) and electrodes (22 & 22) the top portion (6)
of the body having at its center an opening for the introduction of the armature
shaft.
Fifth In a mercurial electric current meter a body or receptacle (3) being

page_text: of insulating material pressed or moulded around the pole pieces
and the electrodes (22 & 22) holding them in their respective places.
and (5):
Sixth: In a mecurial electric current meter a body or receptacle consisting
of the lower part (3) and the upper part (6) adapted to fit each other with a
mercury tight joint, and embracing the pole pieces (N & S) and electrodes (22 & 22)
and adapted to a stopper to close mercury tight the opening around the shaft in
the top, when transported.
Seventh: In a mercurial electric current meter a receptacle (3) containing
the mercury and surrounding the armature in combination with the magnet (1).
so formed and placed that it shall enclose the receptacle and armature directing
its lines of force through them; for the purposes as shows and specified.
•
:
Eighth In a mercurial electric meter an armature circuit consisting of an
armature submerged in mercury, conductors leading the current to and from the
mercury and armature so that it will pass through the armature in going
from one of said conductors to the other; said armature circuit to be connected
in shunt to another circuit containing an adjustible resistance, by means of which
the speed of the meter shall be corrected."
Ninth In a mercurial electric current meter means of adjusting the speed of
rotation consisting of the shunt (19) and the sliding jumper (20) of so high a
resistance as to take from armature but sufficient current for means of correction,
substantially as specified..
Tenth The ballast weight (7) carried by the shaft (9) and serving to submerge
the armature when released and being adapted to be lowered locking and closing
mercury tight the opening in the cover (6) when required for transportation.
Eleventh: In a mercurial electric meter, a part (7) carried by the shaft (9)
when in operation and being threaded at its lower end so as to be screwed to the
threaded neck on cover (6), thereby effectually sealing and locking meter for
transportation.
Twelfth In a recording electric meter having a rotating armature; a
differential gear driving a recording mechanism always in a given direction
regardless of the direction of rotation of the driving shaft, and consisting of
the driven ratchet wheel (33); spur wheels (37) and (38) having a common shaft
and palls (34) and (34) and driven in directions opposite to each other by the
pinion wheels (35) and (36) respectively as shown and specified.
Thirteenth The combination in a housing for a recording electric meter of
the part (17) serving at once as back of housing and support for meter;
with the cover (29) covering all other sides and being adapted to back, by being
lowered a short distance whereby they shall become engaged at the top, then in
turn the bottom of cover (29) after being thrown back square with the back
part (17) will be locked at bottom to it, substantially as shown and specified..
Fourteenth In a recording electric meter the bolt (21) held by bottom portion
of meter back and being adapted to drop through an opening in bottom of cover
thereby locking cover in place; substantially as specified. -
Dated this 3rd day of June 1899.