AN ELECTRIC METER, OR CURRENT REGISTERING INSTRUMENT
Year: 1885

page_text: FRANCIS FANE YEATMAN 12 Calthorpe St Gray's Inn Rd. W.C. do hereby declare
the nature of my invention for AN ELECTRIC METER, OR CURRENT REGISTERING
INSTRUMENT to be as follows:-
This Electric Meter, or Current Registering Instrument, consists essentially of
two disks, preferably of copper, cast upon opposite ends of the same hollow shaft or
tube, also preferably of copper; one of these disks being considerably larger than
the other.
These two disks are so placed with regard to two metal troughs, that the lower
part of the periphery of one disk is within one of the metal troughs, & the lower
part of the other disk within the other trough.
.
The two troughs are to contain sufficient mercury to form electrical contacts
between each trough & its disk..
:
On either side of the larger disk is placed a magnetic pole.
When a current of electricity is caused to pass from one trough to the other by
way of the disks & their connecting shafts; the disks will be caused to revolve,
& the speed of their revolution will depend upon the strength of this current &
also upon the strength of the magnetic field in which the larger disk is placed.
The shaft, upon which the two disks. are cast, being hollow, a small steel rod is
passed through and firmly fixed within it, the tube & steel rod are electrically
insulated from one another. The ends of the steel rod project considerably beyond
the two disks & form the true shaft, upon which the disks revolve.
One end of this steel rod is connected to a suitable train of toothed wheels;
which wheels bear upon their axes pointers, which as they revolve indicate upon
dials either the Ampere-bours of the current, which it is desired to register, or else
certain numbers from which the Ampere-hours can be obtained by means of a
constant.
In place of the above mentioned magnetic poles, either a conductor through
which a current of electricity is passing, or only one pole of a magnet, may be
used.
D
1
1
. 1000

page_text: An Electric Meter or Current Registering Instrument.
I FRANCIS FANE YEATMAN of 12 Calthorpe Street Grays Inn Road W.C. in
the county of Middlesex 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 electric meter or current registering instrument consists essentially of two
discs advantageously of copper, fixed upon opposite ends of the same hollow shaft
or tube also advantageously of copper, one of these discs being considerably.larger
than the other. These two discs are so placed with regard to two metal troughs or
troughs with metal connections that the lower part of the periphery of one disc
shall be within one of the metal troughs and the lower part of the other disc
within the other trough. The two troughs contain sufficient mercury to form
electrical contacts between each trough and its disc. On either side of the larger
disc a magnetic pole is placed in any suitable position.
When a current of electricity is caused to pass from one trough to the other by
way of the discs and their connecting shaft the discs will be caused to revolve and
the speed of their revolution will depend upon the strength of this current and also
upon the strength of the magnetic field in which the larger disc is placed.
The shaft or tube upon which the two discs are fixed being hollow a small steel
rod is passed through and firmly fixed within it; the tube and the steel rod are
electrically insulated from one another. The ends of the steel rod project con-
siderably beyond the two discs and form the true shaft upon which the discs
revolve.
"
At either end of this steel rod is attached a suitable train of toothed wheels, which
wheels bear upon their axes pointers which as they revolve indicate upon dials
either the Ampere-hours of the current which it is desired to register or else contain
numbers from which the Ampere-hours can be obtained by means of a Constant."
In place of the above mentioned magnetic poles either a conductor through
which a current of electricity is passing or only one pole of a magnet may be used.
One or both discs may be slit radially or in place of discs hubs and radial arms
may be used.
The whole may be set horizontally in which case the edges of discs or ends of
radial arms must be bent to fit into circular troughs containing mercury.
Or the arms may be set at any convenient angle so as to dip into the above
named circular trough.
This instrument or apparatus may also be used to register the charging current
of secondary batteries and by the addition of a solenoid or electro-magnet be made
to cut off the charging current when the batteries are fully charged.
And in order that my invention may be more clearly understood and readily
carried into practice I will proceed to describe my said invention with reference to
the accompanying drawings.

page_text: a and b are two discs fixed upon opposite ends of the hollow shaft or tube c the
disc a being considerably larger than the disc b the lower part of the larger disc a
being within the mercury contained in the trough e and the lower part of the small
disc b being within the mercury contained in the trough d which rests upon
support w and n is the magnetic pole or poles or it may be a conductor through
which a current of electricity is made to pass.
The hollow shaft c upon which the two discs a and b are fixed is mounted upon
a suitable rod or shaft f which is firmly fixed within and insulated from the hollow
shaft c and at the point (or at the opposite end) of the rod f a suitable train of
wheels and dial or dials are mounted whereon is indicated the amount of electricity
passing as when the current passes from the wire e¹ through the trough e and the
mercury contained therein to the disc a and thence by means of the hollow shaft c
to the disc b which through the mercury contained in the small trough d completes
the circuit with the wire d' connected to the small trough d and causes the discs
to revolve as the current passes through.
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. The improved arrangement and construction of an electrical meter or
current registering instrument substantially as described and illustrated by the
drawings hereto annexed.
2. The use and application in an electrical meter or current registering
instrument of metal discs such as a and b in conjunction with troughs containing
mercury as and for the purpose hereinbefore described and represented in the
drawings hereto annexed.