A Method of and Apparatus for Utilising Fixed Electromotors for Elevating, Hauling, and other like Applications.
Year: 1890

page_text: Date of Application, 14th June, 1890
Complete Specification Left, 16th Mar., 1891-Accepted, 13th June, 1891
PROVISIONAL SPECIFICATION.
A Method of and Apparatus for Utilising Fixed Electromotors for
Elevating, Hauling, and other like Applications.
We, JOHN GRICE STATTER and SYDNEY LINTON BRUNTON, both of Alliance
Engineering Works, West Drayton, in the County of Middlesex, Electrical
Engineers, do hereby declare the nature of this invention to be as follows:-
Our invention relates to a method of and apparatus for utilising fixed electro-
motors for elevating, hauling and other like applications, such for example as the
working of cranes, lifts, pumps, winding machines, and hauling machines.
:
Fixed electromotors are at present utilised for the purposes above mentioned by
one of two methods, which for facility of differentiation we shall proceed briefly to
describe with reference to the operations of stopping and reversing. In accordance
with the first method stopping is effected by switching off the current from the
electromotor or from either its armature or its field whilst reversing is effected
by any ordinary form of reversing switch which crosses the leads so as to reverse
the direction of current in the field or in the armature. In accordance with the
second method the electromotor is run continuously in one direction, the mechanical
power being collected by rolling friction. In this case stopping is effected by
removing a friction pulley from contact with the motor pulley; whilst reversing is
effected in a purely mechanical manner by mechanical gearing. Two drawbacks
which the first of these two methods presents are the heavy sparking on the
switches on breaking circuit, and the necessity of employing a graduated resistance
in starting. These drawbacks are avoided in the second method but it is costly
and inconvenient.
In the method which constitutes a part of our invention the drawbacks
mentioned as being present in the first of the two existing methods above referred
to are avoided and cheapness and convenience combined with high efficiency are
obtained.
In
Our method is based upon the employment of a constant current electromotor
fed by a constant current generator that is to say such an electromotor and such a
generator as are respectively adapted to receive and to generate a constant current
independently of any variations of resistance or of counter electromotive force.
practising our said method the current is allowed to traverse the electromotor during
the whole time that the apparatus is in use. Normally we keep the brushes in that
position on the collector at which the armature remains stationary. Starting is
effected by moving the brushes to such a position on the collector that motion of
the armature ensues, the direction of such rotation being determined by the
direction in which the brushes are moved, and the torque and hence the velocity
It will
depending upon the amount of angular displacement of the brushes.
be seen that reversing is effected by moving the brushes from a position on
one side of the normal position before mentioned to a position on the other
side thereof.
It will thus be seen that during the time the apparatus is in use the current is
passing through the electromotor though whilst the brushes are in their normal
position the armature will be at rest.
In order to carry out the distinctive method which we have just described and
which constitutes a part of our invention we employ suitable mechanical trans-
mitting devices which are so designed and arranged as to ensure case of

page_text: starting, equal efficiency at high and low velocities and rapidity and accuracy
of adjustment.
Dated this 12th day of June 1890.
J. G. LORRAIN, M.I.E.E., M.I.M.E.,
Norfolk House, Norfolk Street, Strand, London, Agent for Applicants.
COMPLETE SPECIFICATION.
A Method of and Apparatus for Utilising Fixed Electromotors for
Elevating, Hauling, and other like Applications.
We, JOHN GRICE STATTER and SYDNEY LINTON BRUNTON, both of Alliance
Engineering Works, West Drayton, in the County of Middlesex, Electrical
Engineers, 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:-
Our invention consists of a method of utilising fixed electromotors for elevating,
hauling and other like applications. Amongst such applications we may mention
the working of cranes, lifts, pumps, winding machines and hauling machines.
Fixed electromotors are at present utilised for the purposes above mentioned by
one of two methods which, for facility of differentiation, we shall proceed briefly
to describe with reference to the operations of stopping and reversing. In
accordance with the first of these methods stopping is effected by switching off
the current from the electromotor: whilst reversing is effected by any ordinary
form of reversing switch which crosses the leads so as to reverse the direction of
the current in the field or in the armature. In accordance with the second of these
methods the electromotor is run continuously in one direction, the mechanical
power being collected by rolling friction. In this case stopping is effected by
removing a friction pulley from contact with the motor pulley; whilst reversing is
effected in a purely mechanical manner by mechanical gearing. Two drawbacks
which the first of these two methods presents are the heavy sparking on the
switches on breaking circuit and the necessity of employing a graduated resistance
in starting. The second of these methods has the disadvantages of being costly and
inconvenient.
In the method which constitutes our invention the drawbacks and disadvantages
mentioned as being present in the two existing methods above referred to are avoided
and cheapness and convenience combined with high efficiency are obtained.
In practising our invention we employ a constant current electromotor fed by a
constant current generator, that is to say such an electromotor and such a generator
as are adapted to respectively receive and generate a constant current.
lever or other convenient device is used in connection with the brush-rocker on the
A hand
electromotor so that the position of the brushes may be altered at will.
In the Complete Specification accompanying the Letters Patent No. 2825 of
the year 1887 granted to one of us, namely John Grice Statter, a form of dynamo-
electric machine is described. This machine when run as a generator and fitted
with a regulator of the kind described in the Complete Specification accompanying
our Letters Patent No. 13,320 of the year 1887 furnishes a constant current
under varying conditions of resistance and of counter electromotive force
and is the form of generator which we prefer to employ in practising our present
invention.
The said machine, without the regulator, and with its pole pieces incised as
presently to be described, constitutes, when run as a motor, the best form of electro-
motor for the purposes of our present invention with which we are acquainted. To
incise the pole pieces of the said machine so as to adapt it, when used as a motor,
for our present purposes, we proceed as follows. We first obtain a shaping curve

page_text: (after the manner explained in the Complete Specification accompanying the above
mentioned Letters Patent No. 2825 of the year 1887) with the machine running in
one direction, and cut away the pole pieces in accordance with that shaping curve.
Thereafter we run the machine in the opposite direction, obtain a new shaping
curve, and cut away the pole pieces (previously cut away in accordance with the
shaping curve obtained before) in accordance with this second shaping curve.
thus obtain cavities or orifices in the pole pieces whose form is that of the two
cavities or orifices, obtained from each shaping curve, meeting and running into
each other.
We
It will be understood that when the electromotor is driving mechanism which
requires to be run in only one direction, the pole pieces need only be incised
in accordance with a shaping curve obtained when the machine is run in that
direction.
:
During the time that the machinery with which our invention is employed is in
use we allow the constant current supplied by the generator to traverse the
electromotor. Normally we keep the brushes in that position on the collector at
which the armature remains stationary and this position we shall hereinafter refer
to as the normal position. We start the electromotor, and consequently the mechanism
to which it is coupled, by moving the brushes from the normal position, when as is
well known motion will ensue. The direction of rotation will depend, as is well
known, upon the direction in which the brushes are moved whilst the torque and
hence the velocity will depend upon the amount of angular displacement of the
brushes. We reverse the direction of movement of the electromotor, and con-
sequently of the mechanism connected therewith, by moving the brushes from
a position on one side of the normal position to a position on the other side
thereof.
:
It will thus be seen that during the time the electromotor is in use the current is
passing through it, though whilst the brushes are in their normal position the
armature is at rest.
We desire it to be understood that we do not limit ourselves, in practising the
method which constitutes our invention, to any specific form of constant current
generator or of constant current electromotor. Nor do we limit ourselves to any
particular device or apparatus for moving the brushes upon the collector.
:
In our Provisional Specification we referred to the apparatus by which our
method is utilised and we referred to such apparatus in our title and in our said
Provisional Specification as forming a part our invention. We wish it to be under-
stood that we lay no claim to any apparatus in this Specification.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
The method of utilising fixed electromotors substantially as set forth.
Dated this 14th day of March 1891.
J. G. STATTER.
S. L. BRUNTON.
Per J. G. Lorrain, M. Inst. E.E., M. Inst. M.E.,
Norfolk House, Norfolk Street, London, W.C., Applicants' Patent Agent.