Improvements in Regulators for Electric, Currents.
Year: 1894

page_text: Date of Application, 25th May, 1894
•
Complete Specification Left, 25 h Mar., 1895-Accepted, 27th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in Regulators for Electric, Currents.
J, WILSON HARTNELL, of Benson's Buildings, Park Row, Leeds, in the County
of York, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
-
This invention has reference to a self acting, electrical, governing apparatus, by
which resistances, or their equivalents, are thrown in and out of circuit.
The object of the invention is to provide a simple automatic appliance,
applicable to the starting of electric motors, and that more especially, from a
distant point, without danger of short-circuiting or injuring the motor; and,
further, to supply a similar appliance for regulating the flow, or pressure, of
electric currents generally.
My invention will be best understood by describing its application to a motor for
starting purposes.
The appliance consists of a solenoid or electro-magnet, which, when acted on by
the current, produces a gradual revolution of an axis on which is mounted, a
sequence of conductors, arranged to make successive contacts with points on a
resistance (through which latter the current for driving the motor is passed), in
such a manner that the resistance is gradually reduced, allowing, meanwhile, an
opportunity for the motor to start working.
Attached to the appliance is a dash-pot provided with a valve by which is
governed the time elapsing between the switching-out of the successive resistances.
Directly the current is cut off the solenoid plunger recedes, and the axially
mounted conductors are revolved backward by reason of a counter balance, to
their starting point- the dash pot valve being arranged to permit this to be done
promptly.
The sequence of conductors may take the form of radial arms mounted on the
before-mentioned axis, each being adjustable thereon, so that the distance that one
stands in rear of its neighbour may be regulated. As the axis revolves the arms
successively dip into troughs of mercury, which are respectively connected to the
various resistances. The fixed contact at which the current enters (or leaves)
this sequence of conductors takes the form of a disc and so never breaks contact
with the mercury in its trough. In order to allow contact to be made quickly, the
dash-pot may have recesses, or other equivalents, past which its piston may
travel more speedily, so as to reduce the tendency to spark when a fresh contact
is made.
The conducting arms instead of dipping into consecutive troughs of mercury
may be arranged to dip into a single trough filled with a liquid of low conducting
In such case
power (such as acidulated water) which fluid forms the resistance.
the sequence of arms may be replaced by a continuous spiral.
Or, in place of the troughs of mercury, the arms may form brush, or other
metallic, contacts. In the former case the brushes may either be fixed, or mounted
on the radial arms. In any case the arms may be arranged so as to be easily
adjusted or renewed.
The current round the solenoid may be taken from some point on the main lead,
before it has reached the resistance (supposing it to be on the positive lead), to
the negative. Or it may be taken from some point on the resistance, near to the

page_text: motor. In the latter case it may be so arranged that the solenoid is not sufficiently
excited to alter the resistances unless the motor has started.
The solenoid may be shunt, or compound wound, for a shunt, compound, or
series motor. With a series motor the solenoid may be series wound, and the
electro-magnet together with the counterweight acting on a wheel or cam may be
so contrived as to put the resistances in or out, as the load varies, so as to regulate
the speed.
With a shunt, or compound, motor, its shunt current may be taken
from some point before the resistances are reached so that the field magnets are at
once fully exciting.
The action of the regulator is as follows:-On turning on the current the
resistances, properly arranged, prevent a short circuit, and yet allow the motor to
start and the solenoid removes the resistances as prearranged.
If it be a series motor, to be governed as before-mentioned, then the solenoid
will not pull off all the resistances until the motor is fully loaded-the position of
the solenoid depending upon the load.
If it be a shunt, or compound wound motor, the action on starting will be the
same; except that the magnets of the motor are fully excited directly the current
is turned on, and before the resistances are removed.
If from any cause the current is stopped the resistances are at once replaced in
circuit, and all is left ready for another start, by the action of the counter weight
or its equivalent.
Amongst other advantages of this invention, it may be pointed out that a motor
fitted with this regulator does not require an attendant near it to start it; and,
should the current be cut off (either by stoppage of the engine, or by being
switched off, for example), the motor is given time to restart properly when the
current is again established; whereas, otherwise, the safety fuse would cut off the
current, or the motor would be damaged by being short circuited.
The appliance may also be used for regulating the current for other purposes.
Thus, it may be used to give an approximately equal current with a variable
pressure, say for are lighting in series; or for maintaining an approximately
uniform pressure, say for incandescent lighting.
In some
cases it may be desirable to arrange a second solenoid to work in
conjunction with the primary.
Doted this uk doy of M. 190.1
improvements in Regulators for Electric Currents.
I, WILSON HARTNELL, of Benson's Buildings, Park Row, Leeds, in the County
of York, 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:-
This invention has reference to a self-acting, electrical, governing apparatus, by
which resistances, or their equivalents, are thrown in and out of circuit.
The object of the invention is to provide a simple automatic appliance
applicable to the starting of electric motors, and that more especially from a
distant point, without danger of short-circuiting or injuring the motor; and,
further, to supply a similar appliance for approximately regulating the flow, or
pressure, of electric currents generally.
In order to fully explain my invention I have added four sheets of drawings, to
the various figures on which reference is herein-after made. The same letters refer

page_text: to the same parts or their equivalents, as far as possible, in all the figures; and
arrows point, diagrammatically, the direction of motion.
Figs. 1 and 2 are, respectively, front and side elevations, partly in section, of the
regulating apparatus; and Figs. 3 and 4 are details connected therewith.
Fig. 5 is a side elevation in section of a modified arrangement; and Figs. 6 and 7
are details in side elevation of further contact modifications.
Figs. 8, etc., are diagrams of general arrangements, etc., which will be explained
later.
My invention will be best understood by describing its application to a motor for
starting purposes.
The appliance consists of a solenoid or electro-magnet A, which, when acted on
by the current, produces a gradual revolution of an axis B (by means of a cord A',
running from the plunger A2 over the pulley A³) on which is mounted a sequence
of conductors C to C, arranged to make successive contacts with points D' to D³,
on a sub-divided resistance (through which latter the current for driving the motor
is passed) in such a manner that the resistance is gradually reduced, allowing,
meanwhile, an opportunity for the motor to start working.
Attached to the appliance is a dash-pot, E, provided with a valve arrangement
(shown in Fig. 2 fitted in a piston E', attached to the foot of the solenoid
plunger A) by which is governed the time elapsing between the switching-out of
the successive resistances. Directly the current is cut off, the solenoid plunger A²
recedes, and the axially mounted conductors are revolved backward, by reason of a
counter-balance, F, to their starting point; the dash-pot valve arrangement
permitting this to be done promptly, by reason of a valve of large area, see E²,
whose supporting spring yields when the piston rises. The by-pass hole E³ may
be regulated by a screw-not shown.
The sequence of conductors-of which there may be as many as are called for-
may take the form of radial arms mounted on the before-mentioned axis B, each
being adjustable thereon, so that the distance that one stands in rear of its
neighbour may be regulated. In Fig. 2. the radial arms C₁, etc., are loose on the
shaft and are finally tightened and fixed by the nuts B' at the ends of the shaft B.
As the axis revolves the arms successively dip into troughs of mercury, see D' to D³
in Fig. 2, which are respectively connected to the various resistances G! to G³,
shown in the diagrams, as for instance, in Fig. 8. By increasing the length of
the shaft, and the relative proportions of the arms C and the actuating pulley A³.
any practical number of resistances may be arranged and thrown in and out. Here
and in the diagrams five have been chosen for explanatory purposes. The cords
between the plunger and the counterweight must be so fixed as to allow no slip.
The fixed contact at which the current enters (or leaves) this sequence of
conductors takes the form of a disc, C, and so never breaks contact with the
mercury in its trough D. In order to allow contact to be made quickly the
dash-pot E may have recesses, or other equivalents, past which its piston may
travel more speedily, so as to reduce the tendency to spark when a fresh contact is
made-see Fig. 3, for example, where air-holes H and H2 temporarily join the
upper and lower portions of the dash-pot as the piston passes between.
In Figs. 1 and 2, a slate, or other bed J, has bracketed thereto, two pieces K
and L for supporting respectively the solenoid and the various conductors, etc.,
connected with the regulating shaft B. The latter is preferably supported on
adjustable centres B³, to reduce friction. The arrangement of the solenoid is such
that the plunger is drawn in as the current increases. The tube E and its airtight
cover, is arranged for filling the dashpot with oil.
The conducting arms, instead of dipping into consecutive troughs, of mercury,
may be arranged to dip into a single trough filled with a liquid of low conducting
In such cases
power (such as acidulated water) which fluid forms the resistance.
the sequence of aims may be replaced by a continuous spiral. An arrangement of
this sort is shown in Fig. 5, where the current enters through the mercury trough D
and disc C, and travels along the spindle and spiral which take the place of the

page_text: arms (C1, C2, C3, C4 and C³) as shown. Supposing the toe C to be dipped into
the liquor at the position D, then the current would have to travel in the liquid as
far as the opposite terminal at D'; likewise as the spiral revolved, the distance to
be passed through the low conducting liquor would be reduced as the imaginary
positions D, D³, D2, were passed, and at D' a practical contact would be set up,
and the full current would flow by reason of the spiral at that end having revolved
into full contact with the outgoing términal.
Or, in place of the troughs of mercury, the arms may form brush, or other
metallic, contacts. In the former case the brushes may either be fixed, as shown
in Fig. 6; or mounted on the radial arms as shown in Fig. 7. In any case the
arms, C, etc., may be arranged so as to be easily adjusted or renewed (say as in
Fig. 2), with the faces of the brushes curved to the requisite radius. This
arrangement would only be suited, however, for powerful solenoids.
The conductor A" carrying the current round the solenoid may be taken from
some point on the main lead, before it has reached the resistance (supposing it to
be on the positive lead) to the negative, as shown in diagram Fig. 8. Or it may
be taken from some point on the resistance, nearer to the motor. In the latter
case it may be so arranged that the solenoid is not sufficiently excited to alter'the
resistances unless the motor has started, 'sec, for example, diagram Fig. 9.
In the diagrams the thick lines represent the main leads and the thinner the
shunts. The motors are lettered M and the field magnet M¹. The main current
is shown led on to the switch arm, marked C, which, in the diagram, takes the
place of the arms, C1, C2, C3, C4, and is supposed to be revolved by the solenoid so
as to make contact with the resistance terminals D', D³, D2, D', being afterwards
drawn back into contact with D by the counterweight F-not here shown-when-
ever the current ceases, leaving all ready for another start. It will be understood
that in reality connecting wires are laid between such mercury terminals as D'
to D' shown in Figs. 1 and 2, and the similarly lettered points in the diagram
resistances. The main switch S, shown at S in Fig. 8 etc., may be any distance
away.
The solenoid may be shunt, or compound, wound, for a shunt, compound, 'or series
motor. With a series motor the solenoid may be series wound, and the electro-
magnet together with the counterweight acting on a wheel or cam may be so
contrived as to put the resistances in or out, as the load varies, so as to regulate
the 'speed, as shown in diagram 12. Fig. 4 shows how a cam-which should be
suitably shaped-may be arranged to balance the increasing power of the solenoid
when required. With a shunt'or compound motor its shunt current may be taken
from some point before the resistances are reached so that the field magnets are at
once fully excited as shown in diagram Fig. 8, for a shunt motor. The arrangement
for a compound motor would be the same, only that the main lead after passing the
resistances would be wound on the magnets.
The action of the regulator as applied to starting a motor is as follows: On
turning on the current, the resistances, properly arranged, prevent a short circuit,
and yet allow the motor to start, and the solenoid removes the resistances as
prearranged; Figs. 1 and 2, and diagram Fig. 8.
If it be a series motor, to be governed as before mentioned, then the solenoid will
not pull of all the resistances until the motor is fully loaded the position of the
solenoid depending upon the load; diagram Fig. 12.
If from any cause the current is stopped, the resistances are at once replaced in
circuit, and all is left ready for another start, by the action of the counterweight
or its equivalent.
If it be a shunt, or compound, wound motor the action on starting will be the
same, except that the magnets of the motor are fully excited directly the current
is turned on, and before the resistances are removed.
Amongst other advantages of this invention it may be pointed out that a mótor
fitted with this regulator does not require an attendant near it to start it; and
should the current be cut off (either by stoppage of the engine, or by being]

page_text: switched off, for example) the motor is given time to restart properly when the
current is again established; whereas, otherwise, the safety fuse would cut off the
current, or the motor would be damaged by being short-circuited.
The appliance may also be used for regulating the current for other purposes..
Thus, it may be used to give an approximately equal current with a variable
pressure, as shown in diagram Fig. 10, say for arc lighting in series; or for
maintaining an approximately uniform pressure say for incandescent lighting as
shown in Fig. 11. In these cases a shunt only need be passed round the solenoid.
Fig. 13 shows, diagrammatically, an arrangement of a compound wound solenoid,
working, in this case in conjunction with a shunt wound motor, governed by my
regulator.
In diagram Fig. 14. my regulator is arranged to put resistances in and out of the
magnetic field of a dynamo when it is desired to have a more uniform potential, or
current; the solenoid being excited from the brushes as shown; DD being the
dynamo. A somewhat similar arrangement of throwing resistances in and out of
the magnetic field of a motor may in some cases be resorted to.
The dash-pot is not required except for governing gradually on starting; and its
position may be other than at the foot of the solenoid; for instance it may be
connected with the counterweight and its movements.
In some cases instead of the usual solenoid I use a special magnet so arranged as
to have a minimum magnetic resistance, as shown in Fig. 15. Here A³ is a central
fixed core, surrounded by the solenoid coil A. The fixed pole is A', and the
movable pole or armature is A³. The application is the same as before, the
cord A' from the sling A' being led over the pulley A³. A dash-pot in such a
case can be suitably arranged in connection with the counterweight as before
mentioned.
In some cases it may be desirable to arrange a second solenoid to work in
conjunction with the primary, say when a later, or other independent, action is
desired; but in a general way one solenoid will suffice, and from its axis, B,—
either fixed thereon or geared thereto-two or more sets of resistances (more or
less independent) may be regulated.
Fig. 16 shows, diagrammatically, an arrangement by which a regulator may cut
off part of the current of its solenoid when a prearranged point has been reached.
The two sets of resistances shown would be worked from the same axis B, here
separated for explanatory purposes. In the diagram a specially long contact is
given to the starting terminal of the solenoid resistance as shown to the right hand
of the sketch, where the arm C is putting the first resistance into the solenoid
shunt.
When a motor has a possibility of being dangerously overloaded my appliance
may be arranged to first start it, and afterwards to throw in resistances to meet the
possible danger if the current becomes too strong. In such an arrangement, shown,
diagrammatically, in Fig. 17, the solenoid passes the ordinary working current when
drawn down say two thirds of the stroke, the last third being arranged to throw the
precautionary resistance in. With this in view, reverting to Figs. 1 and 2, the
arm C, for instance, might form a disc, so that when C was drawn out of its.
trough the current would be thrown back and made to travel through the total
resistance again. Or some other special arm or arms may be revolved into action
and so throw the current back through any of the existing resistances, such as have
been prearranged, as shown diagrammatically in Fig. 17 aforesaid, where the
terminal Dº, and D00, throw the current round to D' and D* respectively.
From what has been shown it follows that an outgoing sequence of conductors
may work itself out in favour of an incoming one, which latter, then takes up the
work in the manner prearranged.
Referring to Figs. 1 and 2 (where c, c', c², c³, c, c, are the leads) and diagram
Fig. 8; as the fourth resistance, G', could, when used for starting purposes, be
kept in touch with the terminal of the disc C-even when cut out-the terminal D
would not be necessary when four resistances only were required; or put in another

page_text: way, the five regulating mercury troughs in Fig. 2 could be used for five resistances
provided the last arm C, lifted itself clear of its trough D, and left the current
running direct from C through the last resistance. All resistance terminal
connections overlap one another, of course, so as not to leave gaps between one and
the other as the shaft B revolves.
The regulator may be applied to direct currents generally, and also to alternating
currents to gradually cut out resistances, or to throw out of circuit any choking coils
or supplementary devices, and vice versu, put them in.
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
1. The improved regulator for electric currents, consisting essentially of a set of
conducting arms mounted on an axis, and revolved in and out of contact by the
action of a solenoid and counterbalance, substantially as described herein and shown
on the drawings.
2. The improved regulator, as set out in Claim 1, fitted with a dash-pot, for the
repeated starting (or intermittant restarting) of motors, whether near at hand, or at
a distance, substantially as described herein and shown on the drawings.
3. The modified form of regulator shown in Fig. 5, working in conjunction with
a solenoid and counter-balance, with or without a dash-pot, substantially as described
herein and shown on the drawings.
4. The modified form of solenoid magnet shown in Fig. 15, used in conjunction
with my regulating appliances, substantially as described and shown.
5. The improved regulator arranged, constructed, operated, and operating
substantially as described herein and shown on the drawings, with the object and
for the purpose set fortb.
Dated this 23rd dor of Merah 1905
WM: SNOWDON,
9, Old Bank Chambers, Leeds, Yorks, Agent for the Applicant..