Improvements in Controlling Devices for Electric Motors.
Year: 1897

page_text: Date of Application, 14th Dec., 1897-Accepted, 23rd Apr., 1898
COMPLETE SPECIFICATION.
[Communicated from abroad by HORACE SEE, of No. 1, Broadway, New York,
United States of America, Naval Architect.]
Improvements in Controlling Devices for Electric Motors.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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:-
The invention is a controlling device for electric motors. It is especially
adapted to governing the rudder of a vessel. The apparatus may operate at low
voltage. Its control does not depend for efficiency on the maintenance of the high
voltage necessary to drive the motor, and is independent of fluctuations in the
electro-motive force on the mains. The movement of a handle introduces into the
motor controlling device a series of current impulses of substantially uniform
strength. These impulses correspond in direction to the direction of movement
of the handle, and in number to the extent of said movement. No multiple system
of wiring and no variable resistances in the circuit are employed.
In the drawings Figs. 1 and 2 are diagrams respectively showing the apparatus
when the motor is at rest-and in motion. Fig. 3 is the mechanism for actuating
the apparatus in plan and partial section-and Fig. 4 the same in transverse
section. Fig. 5 is a diagram showing the contact devices.
Similar numbers and letters of reference indicate like parts.
-
1 is a dynamo, connected by + conductor 2 and-conductor 3 with field of
motor 4. The hand controlling mechanism is as follows:-
A is a case of insulating material having metal spiders B, C.
inclined spring contact plates E, E1, E2, E3 and e, e¹, e², e³ and
plates F, F, F, F³ and f, f¹, f², f³. The plates on spider B are
spider C as shown in Fig. 5.
Spider B carries
spider C similar
opposite those on
G is a contact arm, journaled at D and carrying inclined contact plates I, J
having insulated screens L, N on their inner faces. H is the controlling handle.
Spider B connects by wire 11 to conductor 2, and spider C by wire to conductor 3.
Plate J is connected to wire 10 and plate I to wire 12.
Assume handle H Fig. 3 for example is moved to the left carrying contact
plates I, J to right of Fig. 5. Plate J then passes beneath and contacts with
plate f making circuit from conductor 3 through wire 9 to wire 10. Plate I
passes beneath contact plate e, but insulating screen N prevents circuit being
made. Electrical circuit is maintained until plate J passes beyond plate f
If handle H be moved to the right, then plate J will pass over plate F but
insulating screen L will intervene. Plate I will meet plate E and close circuit
Di Q77

page_text: through conductor 2, wire 11, spider B, plate E, plate I and wire 12. Hence when
handle H is turned to the left circuit is made with minus conductor 3 as contact is
made between plate J and successive plates f, f¹ &c.,-and the time of contact
will depend on the width of the plates. When H is turned to right circuit is
made with plus conductor 2 through plate I and successive plates E, E¹ etc.
Assume plates I, J to have been carried to right of Fig. 5 and beyond plates e, f.
On returning to their original middle position plate I will make circuit with plate e
while plate J will be cut off from plate by insulating screen L. Similarly if
plates I, J have been carried to left of plates F, E in returning plate J 'will make
circuit through plate F while plate I will be cut off from plate E by screen N.
In brief; original movement of plates I; J to the right makes minus connection
through the apparatus as each plate f, fl etc., is successively passed over, and
return movement establishes successive plus connections through plates e, e¹ &c.
Movement originally to the left establishes successive plus connection through
plates E, E etc., and return movement establishes successive minus connection
through plates F, F¹ etc.
13, 14, 15, 16 are solenoid electro, magnets having vertically movable cores.
Cores 17, 18 of magnets 15, 16 carry pivoted pawls 19, 20 provided with retracting
springs 21, 22 and engaging with toothed pinion 23. Pinion 23 engages with
sliding rack 24 on which is insulating block 25 carrying metal contact plate 26.
The shaft of motor armature 27 is threaded at 28 and carries sliding finger 30
which when the parts are in position shown in Fig. 1 bears against plate 26.
The motor shaft is threaded also at 31 to engage with sector rack 32 and thus
to actuate a ship's rudder 33 for example. Or 33 may represent the valve of a
steering engine actuated by sector 32. The cores 34 and 35 of electro-magnets 13
and 14 connect by links 36, 37 to lever 38 pivoted at 39. This lever carries
insulated contact plates 40 and 41 and also armatures 42, 43 of solenoids 15, 16.
The plates 40, 41 close contact between pairs of fixed contact plates 44 and 45, 46
and 47, 48 and 49, 50 and 51.
1
The arrangement in circuit and operation of the above parts is as follows:
Assume handle H to be moved to the right, establishing plus connection
through plates I and E. Shunt circuit is made through wire 12, solenoid 15,
wire 52 and conductor 2. Solenoid 15 then raises core 17 and pawl 19. Pinion 23
is thus rotated to the right and rack 24 moved to the left. Circuit is thus broken
between finger 30 and plate 26 and made between finger 30 and bar 24, as shown
in Fig. 2. Solenoid 15 also attracts armature 42 thus tilting lever 38 to cause it
to close circuit between plates 50 and 51 and 44 and 45. The resulting closed
circuit is from conductor 2, by wire 54, through plates 50, 51, wire 56, bar 24,
finger 30, wire 57, fuse 58 and electro magnet 59 to motor armature; then by
wire 60, contact plates 41, 44, 45, wire 61 to conductor 3.
The motor then rotates in definite direction. The period of rotation will depend
upon how many contact plates E, E etc., have been passed over by plate I, and
hence upon the extent of movement of handle H.
As soon as the motor begins its rotation the nut 29. begins its travel on the
screw 28 in a direction toward contact plate 26; until finally the finger 30 on
said nut once more establishes contact with said plate 26. The transverse width
of the contact finger 30 is greater than the width of the insulating material
surrounding the contact plate 26, so that the forward euge of contact finger 30
establishes contact with plate 26, before the rear edge leaves contact with the
bar 24. Therefore there is no break of circuit at any time by the finger in moving
from the body of bar 24 to contact plate 26. When the finger rests wholly on the
plate 26 the circuit that is then formed proceeds as follows:
-
From the plus main conductor 2 by wire 54 to contact plates 40, 50 and 51,
wire 55, wire 62 to solenoid 14, wire 63, solenoid 13, wire 66, contact plate 26,
wire 57 and the armature of the motor to wire 60, contact plates 41, 44, 45, wire 61
and minus conductor 3. The effect of the current energizing the solenoids 13, 14
is to cause them at once to draw their cores into a central position, as shown in

page_text: Fig. 1, thus bringing the pivoted bar 38 into a position intermediate between
the pairs of contact plates, and closing circuit through no pairs. Current is thus
broken in the armature circuit of the motor, and the motor stops, this stoppage
being assisted by the action of the friction brake controlled by the electro-
magnet 59.
4)
The operation of the motor, now concluded, has through the worm screw 31
actuated the rack sector 32, which may be a tiller, and in this way has set the
rudder in definite position, and in that position the rudder remains as long as may
be desired.
Suppose now that it is desired to alter the position of the rudder. If it is to be
turned still further in the same direction in which it has already been moved, then
the handle H is moved still further to the right, causing the contact plate I on
the arm G to meet the other plates e, e', and the same operation already described is
repeated." If however it is desired to return the rudder to its original position, than
it may be assumed that the handle is carried to the left, and as already explained, in
this case, the plate J communicating with the minus conductor 3 moving to the
right of Fig. 5 will establish contact with the plates F, etc., and the effect will
then be as follows; -
Current being established between the minus conductor 3 and the wire 10, the
solenoid 16 is energized and is in circuit with the minus conductor through the
wire 53. It will then draw up its core 18 and lift the pawl 20, which engaging
with the toothed pinion 23 will rotate that pinion to the left, and so move the rack
bar 24 to the right. The contact plate 26 will thus be displaced now to the right
of finger 30 instead of to the left as before, although it will as before establish
circuit through the bar 24. At the same time the solenoid 16 will attract its
armature 43 thus tilting the pivoted lever 38 to establish contact between the pairs
of contact plates 48, 49, 46, 47. The parts being thus arranged, the circuit
proceeds as follows:-
From plus conductor 2 by wire 54 to contact plates 40, 48, 49 through the wire 65
to the armature of the motor 4, thence through the electro-magnet 59 and fuse 58
to wire 57, to finger 30, to bar 24, by wire 56 to contact plates 41, 46, 47 and thence
by wire 61 to the minus conductor 3. It is obvious that the current then passes
to the motor armature in a reverse direction to what it did before, and therefore
the motor rotates in the opposite way, now carrying its nut to the right until
contact is again established between the plate 26 and the finger 30. The circuit
thus formed proceeds as follows:-
From plus conductor 2 by wire 54 around by the path already stated, to finger 30,
and thence by wire 66 to solenoid 13 by wire 63, to solenoid 14, by wire 62 to
contact plates 40, 46, 47, and thence by wire 61 to the minus conductor 3. The
two solenoids 13, 14 then act as before, bringing the lever 38 into a central position
and breaking circuit through the armature of the motor, and causing it to stop
as previously described. If now it be desired to rotate that armature still further
in the same direction, or in other words, to set the rudder at a greater angle in
the same direction, the handle H is moved still further to the left to make contact
with other plates in the controlling device, but, if it be desired to bring the parts
back to their original and central position, then the plate I in returning establishes
a plus connection through the plate e of Fig. 5, thus completing the circuit
through the wire 12 and through the solenoid 15 and wire 52 to plus main con-
ductor 2. Solenoid 15 then draws up its core 17 and the pawl 19 engaging with
the toothed wheel 23 turns it to the right, moving the bar 24 to the left and so
bringing contact plate 26 once more in circuit with finger 30. But by reason of
the energizing of solenoid 15 it has attracted its armature 42 thus tilting the
lever 38 once more into the position shown in Fig. 2. Then the current proceeds
from plus main conductor 2 through the wire 54 through the contacts 40, 50
and 51 to wire 55, wire 62 to the solenoids 13, 14, by wire 63 to solenoid 13 by
wire 66 to contact plate 26, to finger 30, wire 57, fuse 58, magnet 59, armature of
the motor, wire 60, contact plates 41, 44, 45, wire 66 and so to the minus main con-

page_text: ductor. The solenoids 13, 14 then act as already described to centralize the bar 38
and break contact through the armature coils of the motor, as before, thus once
more stopping the motor.
From the foregoing it will be seen that when the handle H of the controlling
device is moved in one direction, no matter from what point it starts, the motor
always rotates in a given direction, and when it is turned in the opposite direction,
the motor always rotates in the relatively opposite direction to what it rotated
before, and that no matter where the starting point of movement may be, the
extent of rotation of the motor in either direction will always depend upon the
number of contact plates that are swept over successively by the contact plates on
the end of the arm.
г
There are no resistance coils or similar devices which are thrown into the
circuit by the movement of the plates J and I from one fixed contact plate to the
other, but, on the contrary, at every contact the unweakened current on the mains
is transmitted to the controlling solenoids 15 and 16, therefore the strength of
the current on the controlling circuit does not vary with the position of the con-
trolling handle, or with the number of positions in which that handle may be
placed. All that is required therefore is that the current shall have sufficient
strength to energize the solenoids 15 and 16 to enable them to operate their pawls
and turn the wheel 23 and so move the bar 24, and for this purpose only a very
small current is required. So that any current which normally exists on lighting
mains will be abundantly sufficient for this purpose, no matter how much it may
fluctuate for lighting purposes, and practically no matter how much it may
fluctuate at the dynamo, provided it does not become at the source diminished to
an extent too great to enable it to control the solenoids. Or to put it another way,
the controlling electrical mechanism here does not depend for its efficiency upon
the maintenance of the constant superior voltage necessary for other translating
devices in the circuit.
I will now refer to certain details of the apparatus shown in Figs. 3, 4 and 5.
The middle portion of the journal D which passes through the hub of the handle
is semi-circular, as shown at M in Fig. 3. The hub is in two parts, one of
which is received upon the convex side of said semi-circular portion of the
journal; the other half of the hub P is loose, and rests against the flat side of the
journal and the edges of the part O as shown in Fig. 3. The part P of the hub
is hollow internally, and in this is a headed rod Q which extends through an
opening in the flat side of the part P, through a hole in the middle of the journal D),
through the hollow arm G and protrudes beyond the end of said arm. On the
rod Q is a collar R and between this collar and a portion of the journal D there
is a spiral spring S encircling said rod, the collar operating to hold the end of the
rod protruding beyond the end of the arm S. The two parts O and P of the
hub are held together by the springs T, which extend between arms u and v pro-
truding from said parts. In the inner periphery of the casing A are recesses as a,
which are placed in midway positions between the successive contact plates on the
spiders.
The operation of the device, thus described, is as follows:-
Assuming the parts to be in the position shown in Fig. 3, when the handle H is
turned to the right in operating the device, the first effect is to move the part P
of the hub independently, so that it tends to turn on a center b on the right hand
side of said semi-circular portion M. This is permitted by the yielding of the
spring T which connects the parts of the hub together. As the handle is moved
still further to the right, the part P of the hub engaging with the head of the
rod Q operates to draw that rod inward and against the action of the spiral
spring S, so that after the handle H has moved a determinate distance, that is
to say, to a distance equal to the distance intervening between the position of the
recess in which the end of the rod Q is represented in Fig. 3 to the next recess on
the left, a, then the rod Q will have been drawn entirely out of the recess in

page_text: which it rests, and by the controlling action of the spring T on the left hand side
of the hub connecting its parts together the arm G will be drawn rapidly past the
contact plate on the left hand side until the end of the arm Q comes opposite the
recess a, when by the expansion of the spring S it will be thrown into the recess.
This operation will occur in moving the handle H in any direction so as to carry
the plates J and I past one pair of contact plates on the spiders, and will thus
cause the contact arm G to be engaged and held in position, and after this impulses
are sent into the apparatus to work it. The object of this is to prevent the
operator from establishing a contact in the controlling device without actually
causing the plates to pass completely over one another.
The plates E, F, e, f, etc., are spring contact plates to enable them to yield as
the plates J and I pass over or under them, as the case may be, and also to insure
a quick break as the plates part company. Instead of making these stationary
contact plates E, F, e, f spring plates, I may make them fixed plates, and make the
plates I, J on the arm G spring plates; one arrangement being the equivalent of
the other.
A safety fuse d may be provided connected to lever c, which lever when the fuse
is melted by a too strong current is drawn by a retracting spring i into contact
with block j and circuit is established anew through a second fuse k. There may
also be a pivoted brake lever m provided with spring n which tends to force it
against disk o on the armature shaft. When the magnet 59 is energized by the
working current the lever is retracted against the pull of the spring, but when the
armature curcuit is interrupted the magnet releases lever m which by the action
of spring n is forced against disk o, and so operates as a friction brake to stop the
rotation of the armature.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent, I declare that what I claim is:-
1. Controlling an electric motor by establishing in an electro-magnetic circuit
closing device a succession of current impulses corresponding in direction to the
deviation of a controlling lever and thereby causing the armature of said motor
controlled by said device to move in a direction corresponding to the direction of
said current impulses and to an extent depending upon the number of said current
impulses.
2. Electrically controlling from a distance a ship's rudder or other adjustable
device by establishing in a controlling device governing the electric motor
actuating said rudder or other device a succession of current impulses of sub-
stantially uniform strength and corresponding in direction to the deviation of a
controlling lever and in number to the extent of said deviation.
3. The combination of an electric motor, supply mains therefor, an electro-
magnet in circuit with said mains, means for producing successive closings of
circuit through said magnet and mechanism actuated by said magnet for establish-
ing circuit in said motor armature, and causing a definite extent of motion thereof
for each closing of circuit through said magnet, substantially as described:
4. The combination of an electric motor, supply mains therefor, two electro-
magnets in circuit with said mains, a movable lever, means controlled by said
lever for producing successive closings of circuit through one magnet or the other
as said lever is deviated to a greater degree in one or the other direction, and
mechanism actuated by said magnets respectively for establishing current in said
motor armature in direction corresponding to the deviation of the lever and for
uniform periods corresponding to the number of successive closings of circuit,
substantially as described.
5. The construction and arrangement of the hand controlling apparatus having
a lever and inclined movable and fixed contact plates, substantially as set forth.
6. In combination with the controlling lever H and rod G a locking device ag

page_text: set forth constructed and arranged to hold said rod in definite position until, after
said lever H shall have been moved a predetermined extent.
Dated this 14th day of December '1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for. the Applicant.