Improvements in Electric Meters.
Year: 1898

page_text: Date of Application, 9th Apr., 1398-Accepted, 4th Mar.,
1899
COMPLETE SPECIFICATION.
Improvements in Electric Meters.
I, WILLIAM DENNIS MARKS, of 901, Montgomery. Avenue, Philadelphia, in the
County of Philadelphia, and State of Pennsylvania, in the United States of
America, 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:-
This invention relates to electric meters of the type employing an electrically
With such meters,
operated pendulum for actuating the register mechanism.
an ampere indicator controls the position of a cam which constitutes a variable
limiting stop for one direction of movement of a pawl carrying arm co-operating
with the register and which is actuated always to the same extent in the other
direction by the pendulum.
The objects are, first, to provide a compact, efficient and accurate meter; second,
to provide an improved case for the meter; third, to provide an improved mag-
netised needle for the ampere indicator.
In the drawings, Figure 1 is a front elevation with the outer plate and register
removed; Figure 2 a side elevation partly in section; Figure 3 an enlarged detail
view; Figure 4 a detached plan view; Figure 5 a front view illustrating the
improved meter case; Figure 6 a section on the line 3-3; Figure 7 a section in
the line 2-2; Figures 8, and 10 detail views illustrating the improved ampere
indicator needle; Figure 11 an elevation illustrating the preferred circuit con-
troller; Figure 12 an enlarged view of the controller;. and Figures 13 to 19
inclusive illustrate modified forms thereof.
17 is
Referring to Figures 1 to 4, 1 represents the case, with a removable front 2
having a glass-covered opening 3 therein. 4 are bosses carrying the meter
mechanism. 6, 6 are ampere indicator coils carried between the front and back.
plates 5 and 5 of the frame. The needle 7 of the ampere indicator is carried by
a shaft S mounted in pivot bearings 9. 11 is the controlling arch on shaft 8
12 is the electrically
and provided with an eccentric bottom working face.
operated pendulum carried on shaft 13 in stirrups 14, 14 pivoted to the back
plate 5 and intermediate plate 10. The pendulum carries a curved core 15
cooperating with the solenoid 16, which solenoid is periodically excited.
the driving cam on shaft 13, 18 is a pawl carrying lever loose on a shaft 19 carried
between the plate 5 and an arm 10. This lever is overbalanced and carries at
its heavier end a weighted spring pawl 20 driving a toothed wheel 21 of a suitable
train of gears 22 for actuating a counter 23 (see Figure 2). A second pawl
prevents return movement of ratchet wheel 21. The other end of lever 18 carries
a pin 24 which engages the bottom surface of arch 11 on each up stroke. The
driving cam 17 is constructed with an eccentric portion extending from one end 26
to about its centre 27, and a concentric portion extending from said centre to the
other end 28, whereby the roller 25 on arm 18 will be engaged by the cam and
depressed to the extent of its eccentricity, after which the plane of said roller will
remain unchanged. The advantage of this cam is, that slight variations in the.
"

page_text: a brake-
movement of the pendulum will not affect the extent of depression of the lever 18.
The arch 11 is formed with a concentric arc 29. Loosely mounted on shaft 13
immediately above are 29 is a sleeve 30 (see Figures 3 and 4) carrying
shoe 31 having a sharpened lower edge 32 engaging arc 29. Sleeve 30 is cut
away at 33, and a pin 34 on shaft 13 works in said cutaway portion. The pin 34
will engage the end of the cutaway portion to elevate the brake-shoe from engage-
ment with the arc 29 immediately after the concentric portion of the driving cam
engages the roller 25, so that the brake will remain elevated from the arc 29
during the short periods of the unattracted and attracted strokes of the pendulum
in which the concentric portion of the driving cam is in engagement with the
roller 25. During this time, the arch is free to adjust itself, but at all other times
it will be locked against movement. 35 is a plumb-line carried by a strand 36
secured to post 37 and by which the verticality of the meter is secured. 38 is a
pointer registering with a scale 39 (see Figure 2) for .indicating the amperes.
To secure the best results, the solenoid 16 has a surplus of power, and a brake is
used cooperating with the pendulum for gradually retarding it on the attracted
stroke. 40 is a weight pivoted to plate 10 by a screw 41. Weight 40 is provided
with a finger 42 normally engaging a bar 43 to sustain the weight. 44 is a stop
on the weight engaging bar 43 when the weight is moved pivotally. 45 is a
spring arranged in the path of movement of the eccentric portion of the driving
cam. The driving cam engaging with this spring first moves the weight pivotally
until the stop 44 engages the bar 43, after which the retardation of the driving
cam is produced entirely by the spring 45.
Referring to Figures 5, 6 and 7 which illustrate the meter case, 1, 1 are the
walls of a suitable box in which the mechanism is placed. 1", 1" are lugs on
the sides of the box through which the supply wires pass. 23 is the register, and
39 the ampere scale, with which the pointer 38 cooperates. 2 is the front frame,
having a continuous external flange 70 fitting around the box. 80 is an internal
flange fitting the inside of the box. Extending through the bottom wall of the
box are a number of pins (one shown in Figure 6) engaging openings in the
flange 80 and holding the frame in place at the lower end. The frame is fastened
at its upper end by a screw 90 engaging a lug 110 on the top wall of the box.
The head of screw 90 is located in a recess 111, and is covered by a seal 112
of wax or lead or similar material. 113 is a seat on the under side of frame 2, and
on which is a glass plate 114 secured by washers 115 and screws 116. 117 is a
brass or tin plate carried in recesses 118 at the top and bottom and on the outside
of the glass. An opening 3 allows the observation of the register and ampere
scale. 120 is a locking bar extending across the plate 117 engaging recesses 121
and through which extends a rivet 122 secured to the plate 117. An opening 123
is formed in rivet 122, and a wire 124 carrying a lead seal 125 is passed through
said opening so as to secure the locking bar 120 in place and prevent removal
of the front plate 117.
In Figures 8, 9 and 10, is illustrated an improved core or needle for an ampere
indicator, based upon the discovery that if a single bar of steel or a steel needle,
or a number of small bars of steel, be tempered glass hard and permanently
magnetized, and be provided with an energizing coil, that all leakage in
magnetism is done away with; that any magnetism lost by sudden shocks is
immediately restored; and that when used in connection with an electric meter
or elsewhere it will be sensitive to the smallest loads and at the same time
absolutely accurate for all loads. 8 represents the shaft, mounted in pivot bear-
ings and carrying the needle 7, shown composed of a bunch of knitting needles.
This needle carries a coil thereon, which is either constantly or periodically
excited and by which the needle will be made extremely sensitive and accurate
for all loads, and there will be no displacing or obliteration of the magnetism
from any causes. The shaft 8 carries the arch 11 which limits the return stroke 5
of the pawl arm for driving the register, as in Figures 1, 2, 3 and 4. The said
shaft is provided with a short adjusting arm 126 by which the shaft and the core

page_text: may be moved slightly to adjust them with respect to the arch, which is held
stationary.
Referring to Figure 11, 6 is the ampere indicator coil, 7 the core actuating
pointer 38 and 11 is the controlling arch. 18 is the pawl arm carrying pawl 20
and engaging wheel 21 of the register. 17 is the driving cam, and 12 the pen-
dulum, having a core 15 actuated by the coil 16. The circuit controller comprises
an arm J pivoted eccentrically to cam 17 and carrying a contact pin J¹ making
contact with the plate K movable with cam 17. Arm J is overbalanced by an
adjustable weight J. L is an insulated guard carried by cam 17 and having an
opening for pin J. The pin J and plate K are shown in contact, closing the
circuit through coil 16 and attracting the pendulum towards the coil, causing
cam 17, contact plate K, pin J' and arm J to swing to the right. As the arm J
passes the centre of gravity, it topples over, breaking the circuit at K. On the
return swing of the pendulum, the guard L moves with the cam to the left, the
pin J working against the right-hand edge of the guard. The arm J will be
again carried past its centre of gravity and will topple to the left, but will strike
below the contact plate K, and contact with that plate will not be made until
the pendulum has almost reached its own centre of gravity. In this way, the
motor circuit is closed for a short period during the last half of each forward
swing, thus maintaining a uniform rate of oscillation of the pendulum.
To get better contact between the pin and contact plate, a contact controller is
employed. Referring to Figures 11 and 12, M is a metal plate, having an arm m
pivoted to cam 17, and having a finger m² bearing against the inner side of the
arm of cam 17. Below finger m¹ is an oblique flange m² normally held against
contact plate K by spring m³ engaging a flange m on plate M. The flange m²
engages the contact pin J' and forces it against contact plate. K with a good
rubbing contact. As contact pin J clears the upper end of the flange m², the
arm J is free to topple over to the right, as described.
In Figure 13, the controller is carried by a spring m³, an arm X being employed
for limiting the movement of flange me towards the contact plate K.
In Figures 14 and 15, a spring m³ is used, formed at its lower end with a
flange m² for forcing contact pin J against the plate K. Spring 'm³ is bent
(Figure 15) to allow pin J¹ to topple past the spring, as explained.
In Figures 16 and 17, N is an arm, cut away on dotted line n, and a head ()
is secured to said arm by a screw o passing through a flange o¹. The lower end
of the downwardly extending arm 0 of head 0 fits the cut n¹ and carries contact
plate K. P is a plate, pivoted at p to head 0 and carrying a block having a
bevelled surface m² engaging the contact plate K. Plate P has a finger 22 at its
upper end, with which a spring m³ engages to force the block in normal
engagement with the contact plate.
Referring to Figures 18 and 19, the spring m³ is secured to a plate Q carried
upon the upper end of the arm N. The lower end of the spring m³ is bent out-
wardly and carries a plate m² engaging the contact plate. Spring m³ is provided
with a finger m² bearing against the inner side of arm N.
The guard L in each form of controller has a clearance at the edge adjacent to
contact plate K, in order to permit good contact between the said plate and
pin J. With the different modifications of contact controller, it will be seen
that in every instance the pin J' will be forced into engagement with the plate K
at a uniform point and with a good rubbing contact, so as to keep the surfaces
clean and bright.
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. An electric meter employing an ampere indicator for indicating the amperes
of current which are passing the meter at all times, the said ampere indicator
being connected to a controlling arch, the position of which controlling. arch

page_text: depends upon the number of amperes of current at any time influencing the ampere
indicator: an electrically operated pendulum which is oscillated at a constant rate
and which operates a driving cam; a lever which is moved always to the same
extent in one direction by said driving cam, but whose return movement is
determined by the aforementioned controlling arch, the said lever having a pawl
at one end which, cooperates with and drives a suitable register, the parts being
compactly arranged as described, whereby a very simple, efficient and compact
electric meter will be obtained.
2. The employment with a meter such as enumerated in Claim 1, of a dead-beat
device for holding the controlling arch stationary during most of the time, but
periodically releasing the controlling arch so that it will be free to adjust itself
to variations in the current influencing the ampere indicator coils.
3. The employment with a meter such as referred to in Claim 1, of an electric
motor for actuating the pendulum, said motor having a surplus of power, and a
brake device which cooperates with the driving cam and which tends to gradually
arrest movement thereof so as to thereby secure positiveness of operation.
4. An improved case for meters, comprising a rectangular box, a frame secured
to the outside of the box, a glass plate carried by the frame, a metallic plate on
the outside of the glass plate, and a locking strip with or without a seal for
securing the same, said locking strip being carried on the outside of the metal
plate, holding the latter in position.
5. An improvement in needles or cores for ampere indicators designed par-
ticularly for use with electric meters of the type referred to in Claim 1 but capable
of other uses, the same comprising a single bar of steel or a steel needle, or a
number of small bars of steel such as a bunch of knitting needles, tempered glass
hard and permanently magnetized and provided with a coil adapted to be periodi-
cally or constantly energized so that all leakage in magnetism will be done away
with, and the magnetism lost by sudden shock will be immediately restored, and
when used in connection with electric meters, the needle or core will be sensitive
to the smallest loads and accurate on all loads.
Dated this 9th day of April 1898.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.