Improvements in Electricity Meters.
Year: 1895

page_text: Date of Application, 28th June, 1895
Complete Specification Left, 27th Apr., 1896-Accepted, 30th May, 1896
PROVISIONAL SPECIFICATION.
Improvements in Electricity Meters.
We, CHAMBERLAIN & HOOKHAM LTD., of Nos. 4 to 6, New Bartholomew
Street, Engineers, and SYDNEY HOLMWOOD HOLDEN, of No. 4, New Bartholomew
Street, Electrical Engineer, both in the City of Birmingham, do hereby declare
the nature of this invention to be as follows:
Our invention relates to electricity meters, and our object is to improve the
starting of the meter, and reduce tendency to error.
In electric meters we find in practice that static friction acts with some variation
or uncertainty in opposing an initial starting force, so that there is some difficulty
in arranging a minimum starting force, which will not at times start the meter
when it should remain stationary.
To obviate this difficulty we apply a larger and more constant force to stop the
meter, and for this purpose we use magnetic attraction, which we may obtain by
means of a small piece of iron fixed on some part of the rotating portion, attracted
by the shunt or permanent magnet.
By this device greater starting forces may be applied without danger of starting
the meter improperly.
Dated his 7th 1...
1005
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicants.
We, CHAMBERLAIN AND HOOKHAM LIMITED, of Nos. 4 to 6 New Bartholomew
Street, Engineers, and SYDNEY HOLMWOOD HOLDEN, of 4, New Bartholomew
Street, Electrical Engineer, all in the City of Birmingham, do hereby declare
the nature of this invention and in what manuer the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
Our invention relates to electricity meters, and our object is to improve the
starting of the meter, and reduce tendency to error.
In electric meters we find in practice that static friction acts with some variation
or uncertainty in opposing an initial starting force, so that there is some difficulty
in arranging a minimum starting force, which will not at times start the meter
when it should remain stationary.
To obviate this difficulty we apply a larger and more constant force to stop the
meter, and for this purpose we use magnetic attraction, which we may obtain by
means of a small piece of iron fixed on some part of the rotating portion,
attracted by the shunt or permanent magnet.
By this device greater starting forces may be applied without danger of starting
the meter improperly.

page_text: Referring to the accompanying sheet of drawings ;
Figure 1 is a general diagrammatic elevation of an electricity meter of one of
our well known constructions, and
Figure 2 is a plan of the armature disc.
In applying our invention to this particular meter, in accordance with one
modification, we arrange to insert or attach a small piece of iron A to the
armature disc, and when the meter stops the iron is attracted by the permanent
brake magnet B forming part of the meter, and the armature is held in one
position with a considerable force, greater that is, than friction, and of a constant
nature. We are thus enabled to apply a more considerable starting force without
incurring any danger in starting when the meter should remain stationary.
Several pieces of iron may be inserted in the disc divided round it to make
certain that the disc stops with the iron near the magnet.
The iron may be arranged at some other part of the meter than the disc, and
separate magnets may be used.
The invention may be applied to any construction of meter.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is.-
The method of increasing the constant force, to prevent an electricity meter
armature from starting wrongly, by the use of magnetic attraction substantially as
and for the purpose hereinbefore described.
Dated this 25th day of Avril 1896.
MARKS & CLERK,
18, Southampton Buildings, Londou, W.C., and
13, Temple Street, Birmingham, Agents for the Applicants.