Year: 1887

page_text: Date of Application, 24th Dec., 1887
Complete Specification Left, 24th Oct., 1888
Complete Specification Accepted, 30th Nov., 1888
I, JOHN GRICE STATTER, of Alliance Engineering Works, West Drayton,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
-
My invention relates to improvements in electro-motors by means of which the
mechanical energy given out can be varied, and the speed kept constant, and this
without loss through sparking the absorption of energy being proportional to the
work done, and varying with the load.
In the complete specification accompanying my Letters Patent No. 2825 of the
year 1887, hereinafter referred to as the "former specification," I describe certain
modified forms of pole piece for dynamo-electric machines, and the method of
determining such modified forms. In my former specification I show how by
employing such modified forms of pole piece in conjunction with a suitable device for
altering the position of the brushes I am able to maintain a constant current through
a variable resistance or under a variable speed of driving.
In my present invention I employ modified forms of pole piece determined in a
similar manner to that described in my former specification: and with such modified
forms of pole piece I employ a device for shifting the position of the brushes upon
the commutator. This device consists of a suitable form of centrifugal governor
connected by convenient mechanism with the brushes on the brush-bar.
The action of an electromotor embodying my improvements is briefly as follows:-
When the load upon the electro-motor is reduced the motor tends to increase its
speed of rotation. This causes the centrifugal governor, acting in the usual well
known manner,
to alter the position of the brushes, so that less electrical energy is
passed through the motor. When the load on the motor is increased its speed of
rotation tends to decrease which causes the centrifugal governor to move the brushes
in the opposite direction to that just mentioned, and so cause more electrical energy
to pass through the electromotor.
J. G. LORRAIN, M.S.T.E., M. Inst. M.E.
Norfolk House, Norfolk Street, London, W.C.,
For the Applicant.

page_text: "
I, JOHN GRICE STATTER, of Alliance Engineering Works, West Drayton, Electrical
Engineer, 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:-
My invention relates to improvements in electromotors by means of which the
mechanical energy given out can be varied and the speed kept constant and this
without loss through sparking-the absorption of energy being proportional to the
work done and varying with the load.
In the complete specification accompanying my Letters Patent No. 2825 of the
year 1887 hereinafter referred to as the "former specification" I describe certain
modified forms of pole pieces for dynamo-electric machines and the method of
determining such modified forms. I shall hereinafter refer to this method as my
shaping curve" method and to pole pieces modified in accordance with this method as
my "shaping curve" pole pieces.
In the complete specification accompanying the Letters Patent granted to Sidney
Linton Brunton and myself and numbered 13,320 of the year 1887 I describe with
reference to figure 6 a form of electric regulator for altering the position of the
brushes on the collector of an electromotor.
In my former specification 1 show how by employing my shaping curve pole pieces
in conjunction with a suitable device for altering the position of the brushes I am
able to maintain a constant current through a variable resistance or under a variable
speed of driving.
In my present invention I construct an electromotor with my shaping curve pole
pieces and I employ therewith or adapt thereto a device for shifting the position of
the brushes upon the commutator.
This electromotor which may be series shunt or compound wound I construct in all
respects similar to a dynamo-electric machine as specified in my said former
specification.
The device for altering the position of the brushes on the collector consists of a
suitable form of centrifugal governor connected by convenient mechanism with the
brushes. I do not limit myself to any particular form of centrifugal governor regulator,
but in practise I find it convenient to employ the ball governor regulator described in
the aforesaid Specification accompanying the Letters Patent granted to Sidney Linton
Brunton and myself.
The action of an electro-motor, having my shaping curve pole pieces, and having
a suitable regulator or device for altering the position of the brushes employed there-
with or adapted thereto is as follows:-When the load upon the electro-motor is
reduced the motor tends to increase its speed of rotation. This causes the regulator
to alter the position of the brushes so that less electrical energy is passed through the
motor less mechanical energy is given out and the speed brought back to within its

page_text: normal limits. When on the other hand the load on the motor is increased its speed
of rotation tends to decrease which causes the regulator to move the brushes in the
opposite direction to that just mentioned and so cause more electrical energy to pass
through the electro-motor more mechanical energy to be given out and the speed to
be again brought back to within its normal limits.
The effect of employing my shaping curve pole pieces to prevent any loss through
sparking however much the position of the brushes may be altered and it will be seen
that the energy absorbed by the electro-motor varies with the work which it does or
in other words is proportional to the load.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
The combination of an electromotor having my shaping-curve pole pieces and a
centrifugal governor regulator substantially as and for the purposes set forth.
Dated this 24th day of October 188e
J. G. LORRAIN, M.S.T.E., M. Inst. M.E.,
Norfolk House, Norfolk Street, London, W.C.,
For the Applicant.