IMPROVE- MENTS IN ELECTRICAL METERS
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of 42 Southampton Buildings
in the County of Middlesex Patent Agent for an Invention of "IMPROVE-
MENTS IN ELECTRICAL METERS " Communicated to him from abroad by
Thomas Alva Edison of Menlo Park in the State of New Jersey United
States of America
PROVISIONAL SPECIFICATION left by the said Thomas John Handford at
the Office of the Commissioners of Patents on the 5th August 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent, "IMPROVEMENTS IN ELECTRICAL METERS " a commu-
nication to me from abroad by Thomas Alva Edison of Menlo Park in the State
of New Jersey, United States of America
The object of this invention is to produce simple and efficient apparatus or means
for measuring the electrical energy consumed in a circuit, which will record
automatically, and will be constructed wholly of mechanically operating parts not
liable to get out of order, and not requiring renewal.
This is accomplished by the use of one or more reciprocating dash-pot plungers
which retard the movement of an electro-magnetic mechanism, operated by the
current in the circuit or a portion thereof, and working by its movement a
recording apparatus.
The dash pot or dash pots employed may be of ordinary construction. But
instead of using a liquid in the dash pots, it is preferred to use the air as a
retarding force, which can be done effectively by making the plungers of large area.
The electro-magnetic mechanism may be a revolving electro-dynamic motor,
located directly in the circuit, or in a shunt therefrom and working a reciprocating,
dash pot plunger, and a recording apparatus by means of a crank and pitman
connection; but it is preferred to employ two electro-magnets acting upon armatures
secured to a pivotted or suspended beam on opposite sides of the point at which
the beam is pivotted or suspended. The bean is connected at its ends to the
reciprocating plungers of dash pots which retard the movement.
magnets are located directly in the circuit or in a shunt therefrom.
These electro-
The beam has

page_text: an arm which works a pivotted circuit controller, making and breaking contact at
mercury cups.
When the electro-magnets are located directly in the circuit the movement
produced by each electro-magnet opens a shunt around the other electro magnet,
and closes a shunt around itself. The electro magnets are thus made to
predominate alternately while the circuit is kept constantly closed.
When the electro magnets are in a shunt from the circuit, the consumption of
electrical energy in which is being measured, the circuit controller makes and breaks
the circuits of the electro magnets alternately, or closes and opens the shunts as in
the first case.
The circuit controller is a pivotted bar having a U shaped arm projecting
The circuit
upwardly and engaging with an arm from the pivotted beam.
controlling bar carries two points dipping alternately in mercury cups, and a central
point dipping permanently in the mercury of a third cup
In order to throw the circuit controlling bar to the limit of its movement after
it has been moved over the centre by the arm from the beam, there is employed a
tube partly filled with mercury or other suitable liquid. This tube is carried by
the bar and the mercury in it flows to one end or the other as the bar tips over
the centre, throwing it to the end of its movement. A weight may be employed
for this purpose as heretofore in circuit controllers of this character but the mercury
tube is preferred
The recording apparatus is worked by two electro magnets, the circuits of which
are made and broken alternately by the circuit controller. When the main
electro-magnets are located directly in the circuit these electro magnets for working
the recording apparatus will be located in the shunt circuits which are completed
alternately around the main magnets; but when the main electro magnets are in a
shunt from the circuit, the recording electro magnets can be placed in the divisions
of this shunt with the main electro-magnets.
The same arrangements of circuits can be used in a shunt around resistance...
The lamps, motors, or other translating devices are preferably arranged in
multiple arc circuits. The speed of the electro magnetic mechanism will vary with
the number of translating devices in circuit, and the recording apparatus will
indicate accurately in any units desired the electrical energy consumed in the
circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas John Handford in the Great Seal Patent Office on the
5th February 1883.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent " IMPROVEMENTS IN ELECTRICAL METERS" A Commu-
nication to me from abroad by Thomas Alva Edison of Menlo Park in the State of
New Jersey United States of America
The said Invention has for its object the production of simple and efficient
apparatus or means for measuring the electrical energy consumed in a circuit,
which shall record automatically and shall be constructed wholly of mechanically
operating parts not liable to get out of order and not requiring renewal.
This object is accomplished by the use of one or more reciprocating dash-pot
plungers; which retard the movement of an electro-magnetic mechanism, operated
by the current in the circuit, or a portion thereof and working by its movement a
recording apparatus.
The dash-pot or dash-pots employed may be of ordinary construction but
instead of using a liquid in the dash-pots, it is preferred to use the air as &
retarding force, which can be done effectively by making the plungers of large
area. The electro magnetic mechanism may be a revolving electro-dynamic motor,
located directly in the circuit, or in a shunt therefrom, and working a reciprocating
dash-pot plunger, and a recording apparatus, by means of a crank and connecting
rod but it is preferred to employ two electro-magnets acting upon armatures
secured to a pivoted or suspended beam, on opposite sides of the point at which
the beam is pivoted or suspended. The beam is connected at its ends to the
reciprocating plungers of dash-pots, which retard the movement. These electro-
magnets are located directly in the circuit, or in a shunt therefrom. The beam has
an arm which works a pivoted circuit controller, making and breaking contact at
mercury cups.
When the electro magnets are located directly in the circuit, the movement
produced by each electro-magnet opens a shunt around the other electro-magnet
and closes a shunt around itself. The electro-magnets are thus made to predominate
alternately while the circuit is kept constantly closed.
When the electro-magnets are in a shunt from the circuit, the consumption of
electrical energy in which is being measured, the circuit controller makes and
breaks the circuits of the electro magnets alternately, or closes and opens the
shunts as in the first case.
The circuit controller is a pivoted bar, having a U shaped arm projecting
upwardly and engaging with an arm from the pivoted beam. The circuit con-
trolling bar carries two points dipping alternately in mercury cups and a central
point dipping permanently in the mercury of a third cup.
In order to throw the circuit controlling bar to the limit of its movement after
it has been moved over the centre by the arın from the beam there is employed a
tube partly filled with mercury. This tube is carried by the bar and the mercury
in it flows to one end or the other as the bar tips over the centre throwing it to
the end of its movement. A weight may be employed for this purpose as hereto-
fore in circuit controllers of this character, but the mercury tube is preferred.
The recording apparatus is worked by two electro-magnets, the circuits of which
are made and broken alternately by the circuit controller. When the main electro
magnets are located directly in the circuit, these electro-magnets for working the
recording apparatus will be located in shunt circuits which are completed

page_text: alternately around the main-magnets, but when the main electro-magnets are in a
shunt from the circuit, the recording electro-magnets can be placed in the divisions
of this shunt with the main electro magnets.
The same arrangement of circuits can be used in a shunt around resistance.
The lamps, motors or other translating devices are preferably arranged in
multiple arc circuits. The speed of the electro magnetic mechanism will vary with
the number of translating devices in circuit, and the recording apparatus will
indicate accurately in any units desired, the electrical energy consumed in the
circuit.
And in order that the said Invention may be perfectly understood I shall now
proceed more particularly to describe the same and for that purpose shall refer
to the several figures on the accompanying sheet of drawings the same letters of
reference indicating corresponding parts in all the corresponding figures.
Figure 1 of the accompanying drawings is a view partly diagrammatic of a
meter of the form which it is preferred to employ located directly in the circuit.
Figure 2 a similar view of a meter of the form which it is preferred to employ
located in a shunt from the circuit ; and
Figure 3 a similar view showing an electro dynamic motor employed as the
electro magnetic mechanism.
1, 2, are the main conductors of a house, or other consumption circuit in which
are placed lamps, motors or other translating devices A preferably arranged in
separate multiple are circuits as shown.
The meter is composed of a pivoted or suspended beam B (Figures 1, and 2)
carrying armatures xy on opposite sides of its pivot acted upon by two electro
magnets CD
At its ends, the beam B is connected with reciprocating dash-pot
plungers E F which are preferably of large area and work against the retarding
force of the air in cylinders E', F', closed at one end as shewn or at both ends if
preferred. The beam B has an arm a projecting downwardly from its centre and
engaging with the U shaped stirrup on the end of the arm 6 of a pivoted circuit
controlling bar G. This circuit controller carries a central pin dipping permanently
in the mercury of a cup c and two end pins dipping alternately in the mercury of
cups d e.
The bar Ghas a tube f partly filled with mercury secured thereto for
throwing the circuit controller to the limits of its movement after it is tipped over
the centre by the movement of the beam B. H represents any suitable recording
apparatus, which is preferably worked by two electro-magnets IK acting alternately
upon an armature lever g. With reference to Figure 1 the electro-magnets CD are
placed directly in the conductor 1 of the consumption circuit. Between the electro-
magnets CD a connection 3 is made with the permanent contact cup c.
Outsido
of the electro-magnets C, D, connections 4 and 5 are made with mercury cups e
and d respectively after passing through the coils of the recording electro-magnets
I and K. Conductors 3, 4 and 5 form shunts around the magnets CD which are
completed alternately by the circuit controller, while the main circuit always
remains closed. When the parts are in the position shown in Figure 1, the current
flows from 1 on the right of C, D, through C 3, c, Gd K and 5 to 1 on the left
of C, D. Current will also flow through D, but the shunt 3, 5 being closed around
D its energy will be small compared with that of C. C will draw B down until G is
thrown over the centre, when contact will be broken at d and made at e, K. also
attracting and working the recording apparatus. Now the circuit having been
changed the current will How from 1 on the right of C. D by 4 I e G c 3 D to 1
on the left of CD. The shunt 3, 4 is now closed around C, and hence D will now
predominate, although a small current will flow through C. The beam B will be
tipped in the opposite direction and I will attract g. The same arrangement of
circuits may be used in a shunt around resistance, in which case conductor 1 is
extended through resistance around the magnets CD as shown in dotted lines at
in Figure 1. In Figure 2 the magnets C, D, are in a shunt 6, 7 around resistance
R located in conductor 1 of the consumption circuit. Conductor 7 is divided and
runs to both magnets C D, and from these magnets separate connections 8, 9, extend

page_text: to magnets 1 K and cups d e.
Conductor 6 extends directly to the cup c. In the
position shown in the drawing, the current flows from 1 on the right of R,
by 6, c, G, d, I, 8, C and 7 to 1 on the left of R. Magnets C I are energized, while
the circuit of D and K is broken. The beam B will be attracted by C and the
lever g by I. The circuit controller will be thrown after the beam B has made a
definite movement breaking contact at d and making contact at e
current will flow from 1 on the right of R by 6, c G, e K, 9, D and 7 to 1 on the
Now the
left of R, and D, K will be energized while the circuit of C, I will be broken.
In lieu of the two electro-magnets and beam, the electro-magnetic mechanism
may be a revolving electro-dynamic motor L, located directly in the consumption
circuit, or in a shunt therefrom as shown in Figure 3. The revolving armature of
this motor has a crank arm or wheel h connected by a connecting rod i with a
guided cross head k, which is connected by a rod l with a reciprocating dash pot
plunger M working in a cylinder Mr. The rod is connected directly with the
recording apparatus H, which is worked direct by the main electro-magnetic
mechanisin without the use of extra magnets for this purpose.
stood that the speed of movement of the electro magnetic mechanism in any of the
It will be under-
forms described varies in direct proportion to the variation in the energy consumed
in the circuit in a given time and hence the recording apparatus will give an
accurate record of the consumption that takes place.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the invention secured to me by the hereinbefore in part
recited Letters Patent is.
First: An electrical meter, composed of an electro-magnetic mechanism actuated
by the current against the retarding force of one or more reciprocating dash-pot
plungers and controlled by a circuit changer arranged with connections as set forth
all substantially as hereinbefore described.
Second-In an electrical meter, the combination with a pivoted beam, of electro
magnets tipping such beam in opposite directions, means for retarding the move-
nent, a circuit controller, moved by the beam, and a recording apparatus, the said
circuit controller being arranged with connections to close and open shunts around
he operating electro magnets without breaking the meter circuit or to open
nd close the direct circuits of the operating electro magnets substantially as
erein before described.
Third: An electrical meter composed of an electro-dynamic motor having a
evolving armature connected with a reciprocating dash pot plunger substantially
s hereinbefore described.
In witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this fifth day of February in the year of our Lord One
thousand cight hundred and eighty than