An Automatic Regulator for Dynamo Electric Machines.
Year: 1893

page_text: Date of Application, 24th Aug., 1893
Complete Specification Left, 2nd May, 1894-Accepted, 2nd June, 1894
PROVISIONAL SPECIFICATION.
An Automatic Regulator for Dynamo Electric Machines.
We, SIEMENS BROTHERS & Co., LIMITED, of 12 Queen Anne's Gate,
Westminster in the County of Middlesex, and ERNEST HOLMES, of 99, Maryon
Road, Charlton in the County of Kent, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
When a number of arc electric lamps are worked in series, fluctuations occur in
the resistance of the circuit owing to inequalities in the consumption and regulation
of the carbons. It is therefore necessary to adjust the E.M.F. of the dynamo
which supplies the circuit so that the current may be kept constant, notwithstanding
such variations in the circuit.
This invention relates to means of automatically effecting the required adjust-
ment, by shifting the position of the brushes on the commutator relatively to the
neutral line. For this purpose, the shaft of the dynamo works by gearing a crank
which causes reciprocation of a rod guided through a sleeve, this rod being
connected to a lever jointed to the core of a solenoid. The coil of the solenoid
forms part of the main circuit, and, as the current varies in the circuit, the core of
the solenoid is moved more or less in opposition to the force of gravity so that the
reciprocating rod is thus guided towards the one hand or the other. The motion of
the core can be adjusted by means of a balancing weight and spring attached to
the lever. Surrounding the rod is a pawl shaped collar, which, according as the
rod is guided to right or to left, engages the teeth of a ratchet wheel, one of which
is mounted on each side of the rod. The spindles of both ratchet wheels carry
pinions which are connected through gearing to a ring mounted concentric with
the axis of the dynamo. On this ring is held by spring friction the rocking frame
which carries the brushes, the movement of which is as usual limited by stops.
When, owing to movement of the solenoid core resulting from variation of
current in the circuit, the one or the other of the ratchet wheels is partly turned
by the action of the reciprocating rod, the ring and with it the frame carrying the
brushes is partly turned so as to move the brushes more or less to or from the
neutral line, thus varying the E.M.F. of the dynamo so as to compensate
the resistance in the circuit, and give constancy of current.
As the brush frame
is held to the ring only by friction, it remains at rest against either stop,
notwithstanding that the ring may be moved farther.
Dated this 24th day of August 1893.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
An Automatic Regulator for Dynamo Electric Machines.
We, SIEMENS BROTHERS & Co., LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, and ERNEST HOLMES, of 99 Maryon
Road, Charlton in the County of Kent, 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 :-
When a number of arc electric lamps are worked in series, fluctuations occur in

page_text: the resistance of the circuit owing to inequalities in the consumption and regulation
of the carbons. It is therefore necessary to adjust the E.M.F. of the dynamo
which supplies the circuit so that the current may be kept constant, notwithstanding
such variations in the circuit.
'
This invention relates to means of automatically effecting the required adjust-
ment, by shifting the position of the brushes on the commutator relatively to the
neutral line. For this purpose we employ apparatus constructed and arranged as
we shall describe referring to the accompanying drawings.
Fig. 1 is a vertical section, and Fig. 2 is an elevation part of the cover plate
being broken away to shew the interior.
The shaft A of the dynamo through speed reducing gear B works a crank C
which causes reciprocation of a rod D guided through a sleeve, this rod being
connected by a link E to one arm F' of a three armed lever, another arm F of
which is jointed to the core of a solenoid G; this core is partly counter balanced
by a weight on the third arm F³ and a spring F¼. The coil of the solenoid G
forms part of the main circuit, and, as the current varies in the circuit, the core of
the solenoid is moved more or less up and down, moving the arm F' and with it
the link E to right or left as the case may be. On the link E there is a pawl
shaped collar e, which, according as the link is moved to right or to left, engages
the teeth of the one or the other of two ratchet wheels H H mounted on each
side of the link. The spindles of both the ratchet wheels H¹ H2 carry pinions I
which are connected through a gear wheel J to a ring K mounted concentric with
the axis A of the dynamo. On the ring K is held by spring friction the rocking
frame L which carries the brushes, the movement of which frame is as usual limited
by stops l.
When, owing to movement of the solenoid core resulting from variations of
current in the circuit, the one or the other of the ratchet wheels H1 H2 is partly
turned by the action of the vertically reciprocating link E, the ring K and with it
the frame L carrying the brushes is partly turned so as to move the brushes more
or less to or from the neutral line, thus varying the E.M.F. of the dynamo so as
to compensate the resistance in the circuit, and give constancy of current. As the
brush frame L is held to the ring K only by friction, it remains at rest against
either of the stops 7 notwithstanding that the ring K may be moved farther by the
action of the link E on the ratchet wheels H' H2.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
An automatic regulator for a dynamo electric machine wherein a solenoid having
its coil traversed by the current generated by the dynamo, by more or less
attracting its core, as the current varies causes a pawl collar on a vertically
reciprocating rod to move the one or the other of a pair of ratchet wheels geared
to a ring carrying the brush frame of the commutator, the brushes being thus
moved more or less towards or away from the neutral line for their contact,
substantially as described with reference to the accompanying drawings.
Dated this 28th day of April 1894.
ABEL & IMRAY,
Agents for the Applicants.