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Патент USA US2411763

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Nov. 26, 19460'
A. w. SWINGLE EI'AL
2,411,763
CONTROL SYSTEM
1
Filed Feb. 2,-- 1944
15b
Lon/5pm
851,6 aw _
I
/z
_‘ lnven'tohsz
AP'LTT‘O W.' Swingie,
George H. pe‘t‘tibone,
Joseph E. Dill,
Their‘ Attorney
Patented Nov. 26, 1946
2,411,763
UNITED STATES PATENT OFFICE‘
2,411,783
CONTROL SYSTEM
Artro W. Swingle, Schenectady, George H. Petti
bone, Scotia, and Joseph E. Dill, Schenectady,
N. Y., assignors to General Electric Company, a
corporation of New York
Application February 2, 1944, Serial No. 520,728
4 Claims. (Cl. 172-—239)
This invention relates to control systems, more
particularly to systems for controlling the op
eration of an electric motor, and it has for an
2
I9 comprises contacts Illa to I9)‘, inclusive, and
the group 20 comprises contacts 20a to 20)‘, inclu
sive. Both groups of contacts are mounted on
a supporting member 2|, with the individual con
tacts separated from each other. The member
character.
2| is preferably made of a suitable insulating
A more specific object of the invention is the
material.
provision of. a control circuit arrangement which
The innermost contacts I91: and 20a of the two
minimizes heat losses resulting from circulating
currents.
10 groups are connected to the opposite terminals
Ilb and I40, respectively, of the speed varying
In carrying the invention into e?ect in one form
resistor I4, and the contacts lab and 2017 are con
thereof, a split series ?eld motor is utilized, to
nected together to the terminal I8a of the speed
gether with a directional resistor connected across
varying
resistor l8 and thus to the center tap
the terminals of the field winding and a speed
controlling resistor connected between an inter 15 Ha of the directional resistor. The taps lab, I80,
I8d, and the terminal I88 of the speed varying
mediate tap of the directional resistor and one
resistor
it are connected to the contacts lsc, ISd,
side of the source. These resistors are controlled
I9e,
and
I9], respectively, of the group I9, and
by banks of spring contacts which in turn are
also to corresponding contacts Zilc, 20d, 20c, and
selectively actuated by high and low speed Selsyns.
In illustrating the invention in one form there 20 20! of the group 20. Capacitors 22 and 23 are
connected across the taps I80 and ltd and be
of, it is shown as embodied in the drive portion
tween
midtap I8d and the terminal lie.
of a follow-up control system.
The actuation of the contacts to control the
For a better and more complete understanding
speed of the motor I 0 is controlled by a high
of the invention, reference should now be had to
speed
"?ne” Selsyn receiver 24 and by a low
the following specification and to the accompany 25 speed or
or "c0arse” Selsyn receiver 2!. These
ing drawing of which the single ?gure is a simple,
Selsyn receivers 24 and 25 are electrically con
diagrammatical sketch, partly in perspective, of
object the provision of a simple, reliable, im
proved, and inexpensive control system of this
an embodiment of the invention.
nected to high and low speed Selsyn transmitters,
respectively, (not shown). The high speed Selsyn
Referring now to the drawing, an electric motor
III is connected to drive an object H into posi 30 receiver 24 comprises a rotor member 24a and a
stator member 241) which, in this application, is
tional agreement with a remote controlling object
mounted in ball bearings and is free to rotate. It
(not shown).
is connected through spur gearing 28 and worm
The motor III is a split series ?eld type motor;
gearing 28a to the shaft of the drive motor I II.
‘ i. e., its ?eld winding is divided into two ?eld coils
Ilia and Ilb of opposite polarity to e?ect rotation 35 The ratio of the gearing is such that the ratio be
tween the revolutions of the stator 24b and the
of the motor in either direction when the excita
driven object I I is a suitable number such as 36:1;
tion of one ?eld coil predominates over that of
i.‘ e., the stator 2417 will rotate 36 times for each
the other. The lower brush Iiic of the motor is
revolution of the driven object I I.
connected to one side I 2 of an A.-C. supply source
I2, H. The upper brush I M of the motor is con 40 The low speed Selsyn receiver 25 has a rotor
member 25a and a rotatably mounted stator mem
nected to the common point of the two ?eld coils
ber 26b. The rotatably mounted stator 24!: of the
Ito and llib.
high speed Selsyn receiver is connected with the
A resistor I4 and a capacitor I! are connected
rotatably mounted stator 25b of the low speed
in parallel across the opposite terminals of the
?eld coils Ilia and “lb by means of conductors 45 receiver by means of gearing 21 having a ratio
such that the low speed stator 25?) rotates at a
l8 and II. This resistor is referred to as the
very low speed with respect to stator 24b; e. g.,
directional control resistor. A second resistor II
one revolution for each 36 revolutions of the high
is connected between the center tap Ha of re
speed stator 24b.
sistor I4 and the side I2 of the A.-C. supply source.
This resistor is provided with a plurality of taps 60 For directly actuating the contacts of'the banks
It and 20, a member 28:: located in the space
Ito, I8b, lie, Ild, and I88 to provide for short
between the two banks and mounted on a lever
cireuiting portions of the resistor, thereby to vary
28 is provided. The lever 28 is mounted in a suit
the speed of the motor I0. Consequently, re
able bearing 29 for rotation about the bearing
sistor I 8 is referred to as the speed varying re
Y axis. Rotation of the lever 28 is effected by means
sistor.
55 of a heart cam assembly comprising a heart
To provide for short circuiting the portions of
shaped cam 30 which is secured to the shaft of
the resistor which are de?ned by the taps "a to
rotor 24a and a cam follower 2| mounted on a
lie, inclusive, a plurality of spring contacts are
yoke 22 which is pivotally connected to lever 28.
provided. These contacts are arranged in two
To provide for transferring the control of the
groups or banks It and 20. As shown, the group 60
contacts from the high speed Selsyn receiver to
aria-tee
3
the low speed Selsyn receiver under certain oh
erating conditions; i. e., when the positional dis
agreement of the transmitters and receivers ex
'>
it
the rotor 26a will rotate the heart cam do in a
counterclockwise direction, thereby to move the
member 26a downward. The downward move
ment of member 28a relieves the pressure on the
ceeds a predetermined amount, the lever 28 is
provided with an armature 33 which is attracted
contacts of bank it, thereby successively insert
ing the sections of the speed controlling resistor
in one direction or the other by means of two
electromagnets 3d and 35. The selective ener
i t in the armature circuit and reducing the speed
gization of the operating coils 3M and 35a of these
of motor it. The separation of contacts the and
electromagnets is controlled by means of a heart
lab interrupts the short circuit about the upper
cam assembly 36 which is operated by the low ill half of the directional resistor it. This results
speed receiver 25, together with a pair of'direc
in reducing theexcitation of the split field coil
tional contacts 31 and 38.
Ida to equalize the excitation of both split ?eld
The operation is as follows: At any instant cur‘
coils ltd. and, iEb and restore the standby zero
rents ?ow from one side of the source through
torque condition of the motor ill.
the armature ID of the follow-up motor, ?eld 15
The rotors'25a and ‘25b rotate simultaneously
coils Ida and lob in parallel, upper and lower
with the rotor 26a and stator 2th and in the same
halves of the directional control resistor ill in > directions, respectively. Owing to the 36:1 reduc
parallel to the center tap Ma, speed varying re
tion of gearing 27, the amount of rotation of the
sistor it to the opposite side of the source. Since
rotor 25a and the stator 25b is only one-thirty
the upper and lower halves of the directional 20 sixth the corresponding rotations "of the rotor
control resistor it are equal, the currents cir
24a and the stator 24b of the high speed Selsyn
culating through these halves to the ?eld wind
ing coils Ma and liib are also equal. Con
If the rotation of rotor 25a in a clockwise di
sequently, the torques produced by these currents
rection exceeds a predetermined amount, e. g.,
receiver.
'
’
l
a
'
are opposite so that the net torque acting on the 25 two and one-half degrees, the heart cam 30 will
armature I0 is zero and the motor is at rest.
have rotated to the 90-degree position, at which
When the motor is at rest, the circulating cur
position it is desirable to transfer control to the
rents are reduced to a very low value, owing to
low speed Selsyn 25. The rotation of the heart
the high ohmic resistance of the directional re
cam assembly 36 closes contacts 37, thereby to en
sistor, and thus the standby losses of the motor 30 ergize operating coil Ma. The armature 33 is at
are reduced to a minimum.
tracted toward core member 36, thereby rotating
lever 28 in a clockwise direction to close all the
contacts of bank is which may not have been
the rotors of the transmitters. If the rotation
closed by rotation of rotor ‘Eda. The speed of
of the rotor 29a is in a clockwise direction, the 35 ‘motor i0 is rapidly accelerated to its maximum
cam follower ill will have a component of move
value. As a result, the driven object ii is driven
ment toward the right, thereby to rotate the
in the desired direction at maximum speed and
Rotation of the rotors of the transmitters
causes the rotors-Eda and 25a to rotate to follow
lever 28 in a clockwise direction about the axis
the stators 26b and 251) are driven in a counter—.
of bearing 29. The clockwise rotation of lever
clockwise direction. When the counterclockwise
28 moves the member 280. into engagement with 40 speed of the stators exceeds the speeds of the
contact i9q. As the clockwise rotation of the
rotors of the transmitters to which they are re
rotor 23a continues; contact i9a is moved into
spectively connected, the rotors 255a and 25a will
engagement with contact lsb, thereby short cir
rotate in a counterclockwise direction. When
cuiting the half of the directional control re-p
the rotor 25a returns to within two and one-half
sistor it between the center tap Ma and the ter
degrees of its initial position with respect to the
minal lfib. As a result, more current ?ows
rotor of the low speed transmitter, the heart
through the split ?eld coil iila than ?ows through _ ' cam assembly 36 will open the contacts 37, there
coil I?b, and a net torque is developed which
by to deenergize the operating coil Sta. As a re
causes the motor ill to rotate in a direction which
sult of the deenergization of coil Sta, the arma
drives the stator 24b in a counterclockwise direc 50 ture 33 is no longer attracted by the core member
tion. Owing to the full amount of resistor l8 in
‘34 and, consequently, the control of the contacts
the armature circuit of the motor, the rotation
I9a to WI, inclusive, is restored to the high speed
is at a slow speed. The rotor 24b continues to
Selsyn 26.
rotate in the clockwise direction and at a speed
If the initial rotation of the rotor Eda is in a
which is equal to the di?erence between the speed 55 counterclockwise direction, in response to a ro
of the transmitter rotor and the speed of the
tation of the rotor of the transmitter in a di
stator 26b. A continued clockwise rotation of
rection opposite to that described in the fore
the rotor 24a acting on the heart cam assembly
going, the operation will be the same as that de
causes the member 28a to continue its upward
scribed except that the rotation of the heart cam
movement to close the contacts I90, i901, lee, and 80 30 and lever 28 will be in a counterclockwise di
lQf in succession. With the successive closing of
rection and the contacts 20a to 20f, inclusive, of
the lower bank 20 will be actuated. The closing
these contacts, successive sections of the speed
varying resistor l8 are short circuited, thereby
of contacts 2M and 28b short circuits the lower
increasing the voltage applied across the arma
half of the directional resistor I ti, thereby e?ect
ture and ?eld coil Ilia. As a result, the speed of 65 ing rotation of the motor ii! in the reverse di~
the motor Ill increases until the speed of the
rection. The subsequent successive closing of _
counterclockwise rotation of the stator ‘25b is
contacts 201), 20c, 29d, we, and 20)‘ short circuits
equal to the speed of the rotor of the transmitter.
successive portions of the speed varying resistor
E8 to accelerate the motor H3 in the manner de
When this condition is reached, the rotor Zea is at
scribed in the foregoing.
standstill with the result that the speed of the
Although in accordance with the provisions of
motor i0 is not further increased.
the patent statutes, this invention is described
If, now, the speed of the transmitter is de
as embodied in concrete form and the principle
creased, the speed of the stator 24b does not de
thereof has been explained, together with the
crease at ‘?rst because it cannot change until
the speed of motor ill changes. Consequently, 75 best mode in which it is now contemplated apply
2,411,763
ing that principle, it will be understood that the
apparatus shown and described is merely illus
trative and that the invention is not limited
thereto, since alterations and modi?cations will
readily suggest themselves to persons skilled in
the art without departing from the true spirit
of this invention or from the scope of the an
nexed claims.
What we claim as new'and desire to secure
6
disposed space, each of said banks comprising a
plurality of spring contacts mounted in spaced
apart relationship, a contact of one of said banks
being connected to one terminal of said ?rst re=
sistor and a corresponding contact of the other
bank being connected to the opposite terminal oi
said ?rst resistor and each of the taps of said sec~
0nd resistor being connected to a different one oi.’
the contacts of one of said banks and a corre
by Letters Patent of the United States is:
10 sponding contact of the second bank, an actuat
1. A control system comprising in combination,
ing member mounted in said centrally disposed
a split series ?eld motor having one armature
space for movement in opposite direction, a rela
terminal connected to an intermediate tap of
tively high speed Selsyn receiver for moving said
the series ?eld winding and a connection from
member in a selected direction to initiate the
the opposite armature terminal leading to one
15 successive closing of the contacts of the selected
side of a supply source, a resistor connected across
bank thereby to short circuit a selected portion
said series ?elding winding, a second resistor
of said ?rst resistor to effect rotation of said
connected-from an intermediate tap of said ?rst
motor in a selected direction and to increase its
resistor to the opposite side of said source and
speed, a relatively low speed Selsyn receiver, speed
having a plurality of taps, a plurality of spaced
apart contacts arranged in two banks, a contactv 20 reducing gearing connecting said Selsyns, and
means responsive to a predetermined amount of
of one of said banks being connected to one ter
rotation of said low speed Selsyn receiver for mov
minal of said ?rst resistor and ‘a corresponding
ing said actuating member to an extreme position
contact of the other bank being connectedto the
to close all of said contacts 01' said selected bank
opposite terminal of said ?rst resistor and each
thereby to effect rotation of said motor at maxi
of the taps of said second resistor being connected
to a different one o1r the contacts of one bank and
to a corresponding contact of the second bank,
and means for selectively engaging the contacts
mum speed.
4. A control system comprising in combination,
a split series ?eld motor having one armature
terminal connected to an intermediate tap of the
of one of said banks to close in succession there
by to short circuit a selected portion of said ?rst 30 series ?eld winding and a connection from the
resistor to effect rotation of said motor in ‘a, cor
opposite armature terminal to one side of a sup
responding direction and successively to short
ply source, a resistor connected across said series
circuit portions of said second resistor to vary
?eld winding, a second resistor connected from
an intermediate tap of said ?rst resistor to the
opposite side of said source and having a plu
rality of taps, a pair of banks of spring contacts
separated from each other to provide a centrally
disposed space, each of said banks comprising a
the speed of said motor.
, ‘
I
2. A control ‘system comprising in combination,
a split series ?eld motor having one armature
terminal connected to an intermediate tap of
the series ?eld winding anda connection from,
the opposite armature terminal to one side of a
plurality of spring contacts mounted in spaced
supply source, a ?rst resistor connected across
said series ?eld winding, a second resistor con
apart relationship, a contact of one of said banks
being connected to one terminal of said ?rst re
sistor and a corresponding contact of the other
nected from the midpoint of said ?rst resistor
to the other side of, said source and having a
bank being connected to the opposite terminal of
plurality of taps, a supporting member, a plural 45 said ?rst resistor and each of the taps of said sec
ity of contacts mounted on said supporting mem
ond resistor being connected to a di?erent one of
ber in cooperative spaced apart relationship and
the contacts of one of said banks and a correin two groups separated from each other to pro
sponding contact of the second bank, a pivotally
vide a centrally. disposed space,~the_end contacts
mounted lever provided with an actuating menu
of said groups adjacent said centrally disposed
ber in said, centrally disposed space and also pro
spacebeing connected to opposite terminals of 50 vided with an armature member, a pair of op
said ?rst resistor, and a member mounted with-7 _ posltely disposed electromagnets arranged in co
in said space for movement in opposite direc
operative relationship with said armature for ei
tions to selectively actuate said groups of con
fecting pivotal movement of said lever in opposite
tacts and to close the contacts of the selected
group in succession thereby to short circuit a se
lected half of said ?rst resistor to e?ect rotation
of said motor in a selected direction and succes
sively to short circuit'portions of said second
resistor to vary the speed of said motor.
3. A control system comprising in combination,
a split series ?eld motor having one armature
terminal connected to an intermediate tap of the
series ?eld winding and a connection from the
opposite armature terminal to one side of a sup
ply source, a resistor connected across said series
?eld winding, a second resistor connected from an
intermediate tap of said first resistor to the op
posite side of said source and having a plurality
of taps, a pair of banks of spring contacts sep
arated from each other to provide a centrally
directions, a relatively high speed Selsyn receiver
for moving said lever in a selected direction to
initiate successive closing of the contacts of one
of said banks thereby to short circuit a por
tion of said ?rst resistor to effect rotation of said
motor in a selected direction, a relatively low
speed Selsyn receiver, speed reducing gearing
connecting said Selsyn receivers, and means re
sponsive to a predetermined amount of rota
tion of said low speed Selsyn receiver for selec
tively energizing said electromagnets to move
said lever to an extreme position to close all of
said contacts of said selected bank to e?ect ro- '
tation of said motor at maximum speed.
ARTRO W. SWINGLE.
GEORGE H. PETTIBQNE.
JOSEPH E. DILL.
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