Year: 1899

page_text: We, HARRY PHILLIPS DAVIS, of 327, Neville Street, Pittsburgh, and GILBERT
WRIGHT, of 409, Ross Avenue, Wilkinsburg, both in the County of Allegheny,
State of Pennsylvania, United States of America, Electrical Engineers, do
hereby declare the nature of this invention to be as follows:-
Our invention relates to controllers for electric motors and has for its object
to provide an apparatus which shall operate with a predetermined degree of
rapidity which is independent of the character of the actuating impulse imparted
by the operator. For this purpose we arrange that the controller drum shall be
connected to the operating shaft by a spring movement of the operating shaft
winding up the spring while the drum is held stationary, until at a predeter-
mined point the drum is released and the wound spring causes the rotation
thereof. By this means the operation of the controller is caused to take place
with a speed which is independent of the operator and the unskilfulness or care-
lessness of said operator is therefore eliminated as a factor in the operation.
In the accompanying drawings,
Figure 1 is a plan view of one form of our controller, the conductors leading
to and from the motor and the pulley or hand wheel for operating the controller
being omitted.
Figure 2 is a view of the controller partially in end elevation and partially
in section.
Figure 3 is a detail view of the cam shewn in Figure 2.
Figure 4 is an elevation of the end opposite to that shewn in Figure 2.
Figure 5 is a detail view of a portion of the mechanism shewn in Figure 4.
Figure 6 is a transverse sectional view of the controller.
Figure is a diagram of the motor, the controller circuits and a circuit
opening and closing switch.
Figure 8 is a view of the controller, partially in side elevation and partially
in longitudinal section.
Figures 9, 10, 11 and 12 are diagrams of the electric circuits corresponding
to the four running positions of the motor.
Figure 13 is an end view of a modified form of controller adapted for a direct
current motor and

page_text: Figure 14 is a diagram of motor and controller circuits adapted for direct
currents.
Referring now to Figures 1 to 12 of the drawings, the supporting base 1 of
the controller is provided at its respective ends with standards 2 and 39 upon
which is mounted a shaft 3 so as to be capable of partial rotation by means of
a pulley, hand-wheel or other device (not shewn) keyed to a sleeve 4 that sur-
rounds and is rigidly fastened to the end of the shaft that projects beyond the
standards 2. Two laterally projecting arms 5 are rigidly fastened to the sleeve 4
or constitute integral parts of the same. Each arm 5 has an inturned end 51
so located as to engage the adjacent standard when the shaft is rotated in the
proper direction.
Keyed or otherwise rigidly fastened upon the shaft 3 adjacent to the standards 2
is a cam 6 having two oppositely projecting arms 61 and 62.
Loosely mounted upon shaft 3 adjacent to cam 6 is a sleeve 7 to which is
fastened one end of a helical spring 8, the latter being coiled about the shaft as
is clearly shewn in Figure 8.
The sleeve 7 is provided with a lug 71 that projects laterally towards stand-
ards 39 and with a lug 72 that projects laterally in the opposite direction into
the path of movement of the arm 6b of the cam 6. The end of helical spring S
opposite to that which is fastened to sleeve 7 is rigidly fastened to a sleeve 9
also loose upon the shaft 3. This sleeve 9 is also provided with two oppositely
projecting lugs 91 and 92. A collar 10 is keyed or otherwise rigidly fastened
to the shaft between the standards 39 and the sleeve 9, and is provided with a
lug 101 in position to engage the lug 91 when the shaft is rotated in the proper
direction for such engagement. Journaled upon the two sleeves 7 and 9 is a
drum 11 having metal ends 12 and 121 and an intermediate body of non-con-
ducting material 111, this body being provided with the strips or blocks 13 of
conducting material which are suitably arranged and connected as will be herein-
after more fully described, in order to effect the circuit changes necessary for
proper control of the motor. Mounted upon the base in position to engage
these drum contact pieces 13 as the drum is rotated are contact fingers 14 which
constitute the stationary terminals for the electric circuits, there being six of
these contact fingers on each side of the drum in the form shewn.
The metal end 12 of the drum 11 is provided with a lug 122 located in the
path of movement of the lug 71 on sleeve 7 and with a flange 15 the major
portion of which is in the arc of a circle which is concentric with the surface
of the drum, but which, at its middle point is recessed to form a notch 151. A
holding pawl 16 is pivoted at one end to the base and is provided at its other
end with a roller 17 of such dimensions and so located as to bear upon the
cam 6 and the rim 15 and to fit into the recess 151 in the latter, when the drum
is in proper position for such engagement. This holding pawl 16 is drawn
inward toward the drum by means of a coiled spring 18, one end of which is
fastened to the pawl intermediate its ends, the other end being fastened to a
suitable projection on the base 1.
The end 121 of the drum is provided with a cam 19 having three projecting
portions 191, 192, and 193 of such form as to give the cam somewhat the shape
of a clover leaf.
At one side of the base 1 and in transverse alignment with the cam 19, an
arm 20 is pivotally mounted. The upper end of this arm is pivotally connected
to a pair of arms 21 between which is journaled a roller 22 in such position
as to rest upon the cam 19. A pair of shorter arms 23 parallel to the arms 21
are connected to the latter by curved links 24. The arms 23 are provided with
a roller 25 which is in contact with the cam 19, at the side opposite to that
which engages with the roller 22. Since the links 24 connect the pins on which
the rollers 22 and 25 are mounted, a parallel motion of the arms 21 and the
arms 23 obviously results when the cam is rotated.
The free ends of the arms 21 are pivoted to the stem 26 of a piston 27. This .

page_text: piston is located in a cylinder 28 which is filled or partially filled with glycerine
or other suitable fluid to give the desired dashpot effect.
The mechanical operation of the controller is as follows: Assuming that the
controller is in its zero or "off" position and regarding it from the end shewn
in Figure 4, if the shaft 3 be rotated by the operator in a clockwise direction,
the arm 62 will engage the lug 72 on the sleeve 7 and thus wind the spring 8
until the arm 61 comes into engagement with the roller 17 on the holding pawl 16
and moves it out of the locking notch 151. When this action takes place, the
drum 11 will turn quickly under the action of the spring and at a certain
definite speed determined by the strength of the spring, the construction and
adjustment of the dashpot mechanism, etc., a sufficient distance to bring the
sets of contact pieces 13 corresponding to the initial speed of the motors into
engagement with the contact fingers 14. The further movement of the drum
to bring the contact pieces corresponding to maximum motor speed into engage-
ment with the fingers will be effected slowly by the spring 8, the rate of move-
ment being determined by the dashpot mechanism and the cam and lever
mechanism between the same and the drum.
In returning to the zero position, the drum is free to turn with the shaft,
since the roller 17 moves freely over the cylindrical portion of the flange 15, and
there is no retardation due to the dashpot.
If it now be desired to rotate the drum in the opposite direction to that above
described, that is, in a contra-clockwise direction, in order to operate the motor
in the reverse direction, the drum will be held stationary by the holding pawl
until the arm 62 comes into engagement with roller 17, when the spring 8 will
serve to rotate the drum quickly to the first running position, the slow move-
ment to the second position being effected by the means and in the manner
already described. The winding of the spring when the shaft
direction last described is effected by the engagement of the lug 101 on the
rotated in the
collar 10 with the adjacent lug 91 on the sleeve 9.
wound up from the other end of operating shaft.
That is to say the spring is
The electrical circuits and circuit changes shewn in Figure 7, and in Figures 9
to 12 are those which are employed when the controller is adapted and used
for controlling the operation of an alternating current induction motor.
In the figures just referred to, the circuits 40-41 and 42-13 are supplied
from a two-phase generator of suitable construction (not shewn), a switch 29
being employed for opening those circuits when desired. The motor 30 may
also be of usual construction, that is, a two-phase induction motor, and in
order to run this motor in either direction and at different speeds, we employ
two auto-transformers 31 and 32, one for each circuit. In each case a hand
switch 33 is shewn in order that one fourth, one half, or three fourths of the
primary voltage may be thrown upon the motor in the first position, the switch
being shewn in the drawings as connected at the middle point so that one-half
the primary voltage is thrown upon the motor in the first position of the controller.
In the first position corresponding to a clockwise movement of the controller
haft from the zero position, one-half of the line voltage is thrown upon the
notor, the entire winding of each transformer being in the generator circuit
nd one half of such winding in the motor circuit. See Figure 9. In the
econd and final position of the drum, when rotated in a clockwise direction
rom the zero point, the auto-transformers are cut out of circuit and the full
ine potential is therefore thrown upon the motor. See Fig. 10. The circuits
n Fig. 11 correspond to the first running position when the drum is moved
na contra-clockwise direction, and in this case, the circuits are the same as in
igure 9, of half the line voltage being on the motor, except that one of the
hases is reversed, thus reversing the direction of rotation of the motor shaft.
Figure 12 the circuits correspond to the second running position when the
rum is moved in a contra-clockwise direction, one of the phases being reversed

page_text: and both converter windings being out of circuit, thus putting the entire line
voltage on the motor and securing maximum speed.
The operation of the drum by the wound-up spring serves, as will be readily
seen, to throw the drum quickly into the first position when it is released by
the removal of the roller 17 on the holding pawl 16 from the notch 151, but
the movement from the first to the second position cannot take place until the
dashpot cylinder has had time to move through the maximum portion of its
stroke, thus enabling the motor to come up to half speed before the full voltage
is thrown upon it and making the control of the motor independent of the
speed with which the operator moves the operating lever or rope.
In Figures 13 and 14 we have illustrated such modifications of the apparatus
already described as are desirable in order to adapt it for use in connection with
direct current motors. The operating and governing mechanisms are or may
be the same as those already described with the exception of the flanges 152
corresponding to the flanges 15 of Figures 1 to 8. This flange 152 is provided
with two notches 153 and 154 in order that the drum may be stopped at such a
position as to avoid short-circuiting the motor armature when thrown from
either on position to the "off" position.
"
"
It will be understood from the development of the controller drum shewn in
Figure 14 that the fingers 141 and 142 co-operate with the contact strips 131
on the drum to progressively cut out the resistance 45 as the drum is rotated
in either direction from either "off" position; that the direction of the current
flow through the armature 46 is reversed by reversing the direction of rotation
of the drum from the zero position, and that a closed circuit including the
armature 46 and field-magnet windings 47 and 48 is maintained during the time
that the line current is cut off.
It is to be understood that the dashpot and cam and lever mechanisms will
be so adjusted as to ensure the degree of initial movement and the rate of
subsequent movement that are adapted to the number and arrangement of the
drum contacts and that the details of construction may be varied within com-
paratively wide limits without departing from our invention..
1000
Improvements in Controllers for Electric Motors.
We, HARRY PHILLIPS DAVIS, of 327, Neville Street, Pittsburgh, and GILBERT
WRIGHT, of 409, Ross Avenue, Wilkinsburg, both in the County of Allegheny,
State of Pennsylvania, United States of America, 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:-
Our invention relates to controllers for electric motors and has for its object
to provide an apparatus which shall operate with a predetermined degree of
rapidity which is independent of the character of the actuating impulse imparted
by the operator. For this purpose we arrange that the controller drum shall be
connected to the operating shaft by a spring movement of the operating shaft
winding up the spring while the drum is held stationary, until at a predeter-
mined point the drum is released and the wound spring causes the rotation

page_text: thereof. By this means the operation of the controller is caused to take place
with a speed which is independent of the operator and the unskilfulness or care-
lessness of said operator is therefore eliminated as a factor in the operation.
In the drawings filed with our Provisional Specification Figure is a plan
view of one form of our controller, the conductors leading to and from the motor
and the pulley or hand wheel for operating the controller being omitted.
Figure 2 is a view of the controller partially in end elevation and partially
in section. Figure 3 is a detail view of the cam shewn in Figure 2. Figure 4
is an elevation of the end opposite to that shewn in Figure 2. Figure 5 is a
detail view of a portion of the mechanism shewn in Figure 4. Figure 6 is a
transverse sectional view of the controller. Figure 7 is a diagram of the motor,
the controller circuits and a circuit opening and closing switch. Figure 8 is a
view of the controller, partially in side elevation and partially in longitudinal
section. Figures 9, 10, 11 and 12 are diagrams of the electric circuits corre-
sponding to the four running positions of the motor. Figure 13 is an end
view of a modified form of controller adapted for a direct current motor, and
Figure 14 is a diagram of motor and controller circuits adapted for direct
currents.
Referring now to Figures 1 to 12 of the drawings, the supporting base 1 of
the controller is provided at its respective ends with standards 2 and 39 upon
which is mounted a shaft so as to be capable of partial rotation by means of
a pulley, hand-wheel or other device (not shewn) keyed to a sleeve 4 that sur-
rounds and is rigidly fastened to the end of the shaft that projects beyond the
standards 2. Two laterally projecting arms 5 are rigidly fastened to the sleeve 4
or constitute integral parts of the same. Each arm 5 has an inturned end 51
so located as to engage the adjacent standard 2 when the shaft is rotated in
the proper direction.
Keyed or otherwise rigidly fastened upon the shaft 3 adjacent to the standards 2
is a cam 6 having two oppositely projecting arms 61 and 62.
Loosely mounted upon shaft 3 adjacent to cam 6 is a sleeve 7 to which is
fastened one end of a helical spring 8, the latter being coiled about the shaft as
is clearly shewn in Figure 8.
The sleeve 7 is provided with a lug 71 that projects laterally toward stand-
ards 39 and with a lug 72 that projects laterally in the opposite direction into
the path of movement of the arm 62 of the cam 6. The end of helical spring 8
opposite to that which is fastened to sleeve 7 is rigidly fastened to a sleeve 9
also loose upon the shaft 3. This sleeve 9 is also provided with two oppositely
projecting lugs 91 and 92. A collar 10 is keyed or otherwise rigidly fastened
to the shaft between the standards 39 and the sleeve 9, and is provided with a
lug 101 in position to engage the lug 91 when the shaft is rotated in the proper
direction for such engagement. Journaled upon the two sleeves 7 and 9 is a
drum 11 having metal ends 12 and 121 and an intermediate body of non-con-
ducting material 111, this body being provided with the strips or blocks 13 of
conducting material which are suitably arranged and connected as will be herein-
after more fully described, in order to effect the circuit changes necessary for
proper control of the motor. Mounted upon the base in position to engage
these drum contact pieces 13 as the drum is rotated are contact fingers 14 which
constitute the stationary terminals for the electric circuits, there being six of
these contact fingers on each side of the drum in the form shewn.
A
The metal end 12 of the drum 11 is provided with a lug 122 located in the
path of movement of the lug 71 on sleeve 7 and with a flange 15 the major
portion of which is in the arc of a circle which is concentric with the surface
of the drum, but which, at its middle point is recessed to form a notch 151.
holding pawl 16 is pivoted at one end to the base and is provided at its other
end with a roller 17 of such dimensions and so located as to bear upon the
cam 6 and the rim 15 and to fit into the recess 151 in the latter, when the drum
is in proper position for such engagement. This holding pawl 16 is drawn

page_text: inward toward the drum by means of a coiled spring 18, one end of which is
fastened to the pawl intermediate its ends, the other end being fastened to a
suitable projection on the base 1.
The end 121 of the drum is provided with a cam 19 having three projecting
portions 191, 192, and 193 of such form as to give the cam somewhat the shape
of a clover leaf.
At one side of the base and in transverse alignment with the cam 19, an
arm 20 is pivotally mounted. The upper end of this arm is pivotally connected
to a pair of arms 21 between which is journaled a roller 22 in such position
as to rest upon the cam 19. A pair of shorter arms 23 parallel to the arms 21
are connected to the latter by curved links.24. The arms 23 are provided with
a roller 25 which is in contact with the cam 19, at the side opposite to that
which engages with the roller 22. Since the links 24 connect the pins on which
the rollers 22 and 25 are mounted, a parallel motion of the armis 21 and the
arms 23 obviously results when the cam is rotated.
The free ends of the arms 21 are pivoted to the stem 26 of a piston 27. This
piston is located in a cylinder 28 which is filled or partially filled with glycerine
or other suitable fluid to give the desired dashpot effect.
The mechanical operation of the controller is as follows. Assuming that the
controller is in its zero or off" position and regarding it from the end shewn
in Figure 4, if the shaft 3 be rotated by the operator in a clockwise direction
the arm 62 will engage the lug 72 on the sleeve 7 and thus wind the spring 8
until the arm 61 comes into engagement with the roller 17 on the holding pawl 16
and moves it out of the locking notch 151. When this action takes place, the
drum 11 will turn quickly under the action of the spring and at a certain
definite speed determined by the strength of the spring, the construction and
adjustment of the dashpot mechanism, etc., a sufficient distance to bring the
sets of contact pieces 13 corresponding to the initial speed of the motors into
engagement with the contact fingers 14. The further movement of the drum
to bring the contact pieces corresponding to maximum motor speed into engage-
ment with the fingers will be effected slowly by the spring 8, the rate of move-
ment being determined by the dashpot mechanism and the cam and lever
mechanism between the same and the drum.
In returning to the zero position, the drum is free to turn with the shaft,
since the roller 17 moves freely over the cylindrical portion of the flange 15, and
there is no retardation due to the dashpot.
If it now be desired to rotate the drum in the opposite direction to that above
described, that is, in a contra-clockwise direction, in order to operate the motor
in the reverse direction, the drum will be held stationary by the holding pawl
until the arm 62 comes into engagement with roller 17, when the spring 8 will
serve to rotate the drum quickly to the first running position, the slow move-
ment to the second position being effected by the means and in the manner
already described. The winding of the spring when the shaft is rotated in the
direction last described is effected by the engagement of the lug 101 on the
collar 10 with the adjacent lug 91 on the sleeve 9. That is to say the spring is
wound up from the other end of the operating shaft.
The electrical circuits and circuit changes shewn in Figures 7 and in Figures 9
to 12 are those which are employed when the controller is adapted and used
for controlling the operation of an alternating current induction motor.
In the figures just referred to, the circuits 40-41 and 42-13 are supplied 5
from a two-phase generator of suitable construction (not shewn), a switch 29
being employed for opening those circuits when desired. The motor 30 may
also be of usual construction, that is, a two-phase induction motor, and in
order to run this motor in either direction and at different speeds, we employ
two auto-transformers 31 and 32, one for each circuit. In each case a hand 5
switch 33 is shewn in order that one-fourth, one-half, or three-fourths of the
primary voltage may be thrown upon the motor in the first position, the switch

page_text: being shewn in the drawings as. connected at the middle point so that one-half
the primary voltage is thrown upon the motor in the first position of the controller.
In the first position corresponding to a clockwise movement of the controller
shaft from the zero position, one-half of the line voltage is thrown upon the
motor, the entire winding of each transformer being in the generator circuit
and one-half of such winding in the motor circuit (see Figure 9). In the
second and final position of the drum, when rotated in a clockwise direction
from the zero point, the auto-transformers are cut out of circuit and the full
line potential is therefore thrown upon the motor (see Figure 10). The circuits
in Figure 11 correspond to the first running position when the drum is moved
in a contra-clockwise direction, and in this case, the circuits are the same as in
Figure 9, one-half of the line voltage being on the motor, except that one of the
phases is reversed, thus reversing the direction of rotation of the motor shaft.
In Figure 12 the circuits correspond to the second running position when the
drum is moved in a contra-clockwise direction, one of the phases being reversed
and both converter windings being out of circuit, thus putting the entire line
voltage on the motor and securing maximum speed.
The operation of the drum by the wound-up spring serves, as will be readily
seen, to throw the drum quickly into the first position when it is released by
the removal of the roller 17 on the holding pawl 16 from the notch 151, but
the movement from the first to the second position cannot take place until the
dashpot cylinder has had time to move through the maximum portion of its
stroke, thus enabling the motor to come up, to half speed before the full voltage
is thrown upon it and making the control of the motor independent of the
speed with which the operator moves the operating lever or rope.
In Figures 13 and 14 we have illustrated such modifications of the apparatus
already described as are desirable in order to adapt it for use in connection with
direct current motors. The operating and governing mechanisms are or may
be the same as those already described with the exception of the flanges 152
corresponding to the flanges 15 of Figures 1 to 8. This flange 152 is provided
with two notches 153 and 154 in order that the drum may be stopped at such a
position as to avoid short-circuiting the motor armature when thrown from
either " on position to the "off" position.
وو
It will be understood from the development of the controller drum shewn in
Figure 14 that the fingers 141 and 142 co-operate with the contact strips 131
on the drum to progressively cut out the resistance 45 as the drum is rotated
in either direction from either "off" position; that the direction of the current
flow through the armature 46 is reversed by reversing the direction of rotation
of the drum from the zero position, and that a closed circuit including the
armature 46 and field-magnet windings 47 and 48 is maintained during the time
that the line current is cut off.
It is to be understood that the dashpot and cam and lever mechanisms will
be so adjusted as to ensure the degree of initial movement and the rate of
subsequent movement that are adapted to the number and arrangement of the
drum contacts and that the details of construction may be varied within com-
paratively wide limits without departing from our invention.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A controller for electric motors in which the controller drum is connected
by a spring to its operating shaft, and so arranged that when the handle is
operated in either direction the spring is wound up and the drum is held station-
ary until the operating handle reaches a predetermined point when it is auto-
matically released and rotated by the wound spring.
2. In a controller as claimed in Claim 1 a device for clamping one end of
the spring to the shaft when the latter is rotated in one direction, and the other

page_text: end of the spring to the shaft when it is moved in the opposite direction, sub-
stantially as described.
3. Controllers for electric motors constructed and operating substantially as
described with reference to Figures 1 to 12 or to Figures 13 and 14 of the
accompanying drawings.
01 9T
F. W. LE TALL,
Chartered Patent Agent,
The Westinghouse Patent Bureau,
Westinghouse Building, Norfolk Street, Strand, London, W.C.