Year: 1898

page_text: I, ROOKES EVELYN BELL CROMPTON, of Mansion House Buildings, London, E.C.,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My improvements consist in the combining with a fan driven by an electric
motor a system of fixed blades in the fan and a counter which will register the
number of revolutions of the fan.
The object of my invention is to supply a simple means by which the electrical
energy used by electrically driven ventilating fans or centrifugal pumps or other
apparatus could be registered and charged for by those supplying electricity in
a simple and effective manner and without the necessity of a special electric
meter.
I effect this by arranging that the spindle of the fan or of the electric motor
actuates or drives by a cord or other suitable gearing a counter and in order that
the reading of this counter may indicate with sufficient accuracy the amount of
electrical energy used to drive the fan.
I can arrange that the blades of the fan are so devised that after calibra-
tion they cannot be re-adjusted, my object being that the user of the fan should
not be able by such re-adjustment of the blades to increase the quantity of air
thrown by the fan or its equivalent at a given speed and so to obtain the desired
quantity of air etcetera, by running the fan and motor at a lower speed and
hence registering a smaller number of revolutions.
It will be readily seen that by suitable calibration a given number of revolutions
of the fan can be made to represent a fixed amount of electrical energy, and a
charge for the use of energy for driving the fan can be made at a rate based on
the number of revolutions made by it since the last reading taken by the supply
company's inspector.
I, ROOKES EVELYN BELL CROMPTON, of Mansion House Buildings, London, E.C..
Electrical Engineer, do hereby declare the nature of this invention and in what
[Price 8d1

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement: ―
My improvements consist in the combination of a fan having fixed and unalter-
able blades driven by an electric motor having a counter which registers the
number of revolutions of the fan. The object of this invention is to provide a
simple and ready means of measuring the electrical energy required to work a
fan by any simple counting apparatus which counts the number of revolutions
made by the fan. In order that the number of revolutions may be sufficiently
accurately proportionate to the energy taken, it is necessary that the fan blades
should be so made and secured that they cannot be altered or the angle of inclina-
tion tampered with by the user. If such a contingency is provided against by
locking the plates in a fixed position by a sealed or similar device, the fan
provided with the counter can be calibrated so that the counter can be read so as
to indicate directly the number of Board of Trade units of electricity used, or a
co-efficient may be obtained and attached by which the number of revolutions
can be multiplied or divided so as to convert the figures into Board of Trade units.
Any convenient form of counter having dials registering the number of revolu-
tions may be used and the spindle of this counter may be attached and driven
directly by the spindle of the motor in any convenient manner.
Where fans fitted with these counters are used on a source of public supply the
charge for electrical energy may be made either at the rate of a fixed sum per
1000 revolutions of the fan or the fan might be calibrated by observing the number
of revolutions obtained by passing through the motor one Board of Trade unit and
using the figure thus obtained as a constant to convert the revolutions registered
into Board of Trade units.
As it is of importance that once this constant has been determined the angle
of inclination of the fan blades should not be altered I provide means of prevent-
ing this by attaching either rods or wires to fixed points on the edges of the
blades and I interconnect these rods and wires so that the angle cannot be altered
without cutting or displacing these wires and I attach a seal or other device which
would facilitate the detection of any such alteration or attempted alteration.
There are many other obvious ways of preventing the arrangements of the fan
being tampered with so as to propel a greater quantity of air per revolution than
was the case at the time that it was calibrated and its constant determined but I
have contented myself with describing one only of these methods.
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 combination of an electrically driven fan with a counter for registering
the amount of electrical energy used in driving the fan, substantially as and for
the purposes herein described.
2. The combination of an electrically driven fan with a counter and with a
means of preventing the angle or air propelling properties of the fan being altered
for the purpose of causing the fan to propel a greater quantity of air per revolu-
tion, substantially as and for the purposes herein described.
Dated the 22nd dove of Avant 100
WM. BROOKES & SON,
55 & 56 Chancery Lane, London,
Agents for the Applicant.