Improvements in and relating to Electric Controllers."
Year: 1897

page_text: Date of Application, 19th Oct., 1897--Accepted, 18th Dec., 1897
COMPLETE SPECIFICATION.
"Improvements in and relating to Electric Controllers."
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, of 83, Cannon Street,
in the City of London, Electrical Engineers, do hereby declare the nature of this
invention (which has been communicated to us from abroad by Henry G. Reist, of
Schenectady, in the County of Schenectady, State of New 1ork, United States of
America), and in what manner the same is to be performed, to be particularly
dscribed and ascertained in and by the following statement:-
The present invention relates to electric controllers, which are employed for
regulating the speed and direction of rotation of electric motors.
The invention has for one of its objects to provide, in a single handle controller
for an electric motor or motors, a reversing switch so arranged that a movement
in one direction causes a rotation of the motor armature in one direction, and a
movement in the reverse direction an opposite rotation of the armature, and a
separate switch for regulating the motor coupled to the reversing switch, and
worked from the same handle.
The invention has for another of its objects to provide in a single handle con-
troller two switches mounted on separate supports and connected for simultaneous
operation, the switches being so arranged that one of them has a movement in
two directions, and the other in a single direction.
The invention also has for its object to so arrange the switches that one of them
is moved at a varying rate of speed, while the operating handle is moving at a
given speed from the "off" to
full on position.
The invention further relates to certain novel features in the construction more
fully described and claimed hereinafter.
In the accompanying drawings attached to and made a part of this specification,
Fig. 1 is a plan of an improved apparatus; Fig. 2 is a sectional view showing
the cap plate removed; Fig. 3 is a front elevation partially in section, and Fig. 4
is a diagram of the circuit connections.
Mounted upon the base A are enclosing cases B and C; the case B contains
the resistance switch D, and the case C the reversing switch E. The switch D
is mounted for movement on the shaft D' which is mounted at the lower end
in a bearing D³ formed on the case B, and at the top in a bearing D3, which is a
part. of the cap plate B. The cap plate B' is substantially rectangular and is
secured to the casing B by bolts; at 133 is formed an opening so that access may
be had to the bearing D³, and also to facilitate the removal of the shaft D¹.
The sector F is pivotally supported on the cap plate B1, and is given an oscillat-
ing movement by the parallel links F which connect it with the gear N; the
gear is mounted on the shaft E¹ of the reversing switch) Bolted to the under
side of the sector is a rack F3, and engaging therewith is a segmental gear D
rigidly secured to the shaft D¹. A segmental star wheel H is keyed to the shaft D₁
and engaging with the notches therein is a spring pressed pawl H¹ having a roller
in its outer end. The star wheel and pawl are so arranged with respect to the con-
tacts on the cylinder D and the stationary brushes, that the contacts will stop
in a position making contact with the brushes.

page_text: Mounted on the shaft D' and in electrical connection therewith, are a number
of spiders D having arms e, e¹ e² arranged substantially 120° apart, and carrying
at their outer ends contacts adapted to engage with the stationary rows of
Brushes I, I, I2; the latter are mounted on vertical insulating supports. These
brushes are connected to the resistance by leads 13 in a manner to be hereinafter
described. It will be seen that the spiders D are counterparts of one another
and each is given a slight angular position in advance of the next succeeding
one. By this construction a single pattern can be used for casting them, and by
changing the position of the key slot in each one the desired relation of the spiders
on the shaft is obtained.
The reversing switch E is mounted on a shaft E₁ which is supported at the
top by a bearing E³ formed in the open bottom box J, and at the bottom in a
bearing E³ formed in the vertically extending piece J'; the latter is bolted to
the box J and provided with feet J at the bottom which engage with the inner
periphery of the casing C. Surrounding the switch E and bearing E3 is a circular
casing C preferably made of thin sheet metal and forming a liquid tight casing
for the oil K. The oil provides a simple and efficient means for taking care of
the arcing at the contacts. By supporting both bearings from a point above the
casing, the construction of the casing is much simplified and all leaks, which
invariably occur when a moving portion of al switch projects through the bottom
of the casing, are avoided. The removal of the parts for repairs and inspection is
also facilitated.
To one side of the reversing switch cylinder and mounted upon an insulating
support L which is secured to the vertical piece J¹ is a vertical row of brushes L
engaging with the contacts on the switch cylinder. The box J is provided with
lugs which are secured to the cap plate B by bolts; and on the back side with
a connection board M made of slate or other insulating material; extending from
the board to the stationary brushes L' are leads L2.
On the upper end of the shaft E' is a gear N meshing with the pinion N¹ which
is mounted in a suitable bearing on the top of the box J, and is provided with
an operating handle N³.
Mounted on the shaft E' below the top of the box is a cam 0 (Figs. 1 and 3),
and a spring-pressed lever 01 having a roller on its free end, rests in a groove on
the cam when the switch E is in the "off" position, and holds it against accidental
movement. Located on the top of the box is a dial P divided into three parts,
for indicating the position of the switches.
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With the parts arranged as shown, both switches are in the off" position.
As the handle N2 is rotated to the right, the stationary brushes L' make contact
with the contacts on the switch E. At the same time motion is imparted to the
switch D through the sector F and links F, but the angular movement of sector F
is less at the start than that of switch E, for in the position shown the centre b
of the links is in line with the centre a of the links and the centre of the shaft E.
Hence, at the start, the movement of 6 is substantially at right angles to a line
connecting the centres a and b giving a very slight angular movement to the
sector F, but one which increases rapidly as the gear N moves. This permits
the switch E to fully establish its circuit connections, without requiring more than
a very slight movement of the switch D.
It will be seen that in operation both switches are in engagement with the
stationary brushes, and that they operate simultaneously.
The switch E has a movement in two directions, corresponding to opposite
direction of the armature, but the arrangement of the switch D is such that it
is moved in the same direction, no matter which way the reversing switch is
thrown from the " off" position. By this arrangement the size of the switch 1)
can be reduced to one half, for if it worked both ways a double set of contacts
would be required.
The gearing is so arranged that the handle N2 makes somewhat less than one
revolution while the switches are moving from " off" to the closing position.

page_text: '
Fig. 4 shows a diagram of the circuit connections in which Q represents a three-
phase generator supplying current to the mains 1, 2 and 3.. The induction motor S
is connected by wires 4, 5 and 6 with the brushes of the reversing switch E. The
contacts are so arranged with respect to the brushes that a movement to the left
will establish certain connections, causing the armature of the motor to revolve
in one direction, and a movement to the right will reverse the connections of two
of the wires and consequently two of the phases, thereby causing the armature
to rotate in the opposite direction. This will be understood by those skilled in
the art, from the diagram without tracing the connections from point to point
in detail.
The contacts on the switch D are shown developed on the same plane and are
electrically connected. Between the members of each row of brushes I, I', I is
connected resistance R, and the resistance of the several rows is Y-connected by
the wire 10. The lowest brush in each row is connected by one of the wires 7, 8
and 9 to the secondary member or armature of the motor S. Assuming that it
is desired to start the motor, the circuit is closed at switch E, causing currents
to be induced in the secondary winding of the motor which is closed through
the resistance R. The resistance R is then gradually cut out of circuit by moving
the contacts of switch D to the right with respect to the stationary rows of brushes.
When the lowest contact in each line engages with the lowest brush in each row,
the resistance will be entirely cut out.
If it is desired to reverse the motor, the switch E is rotated in the opposite
direction, so that the second set of reversing contacts will engage with the
stationary brushes, but the direction of movement of the switch 1) is the same
as before.
Although the invention is herein described and shown in connection with a
controller for a three-phase electric motor, it is evident that many of the features
would apply equally well to other types of controllers.
Having now particularly described and ascertained the nature of the said inven-
tion (as communicated to us from abroad) and in what manner the same is to be
performed, we declare that what we claim is:-
1. In a controller for alternating current induction motors, the combination of
a single switch for opening and closing the primary circuit of the motor and for
reversing the motor, and a separating regulating switch in the secondary circuit
of the motor.
2. A controller for alternating current induction motors, comprising a resist-
anco switch for varying the resistance of the secondary circuit of the motor, a
separate reversing switch, and a common operating handle for both switches.
3. In a controller for alternating current induction motors; the combination of
a drum switch connected with the secondary of the motor or motors for speed
and power regulation, and a separate reversing switch mechanically geared or
connected with the regulating switch, said switches being so constructed and
connected that when the reversing switch has been thrown in either direction,
the regulating switch may be actuated throughout its range of movement without
interrupting or changing the circuit connections of the reversing switch.
4. In a controller for an alternating current motor or motors, the combination of
a switch immersed in oil and arranged to make and break the motor circuit, a
second switch arranged to vary the resistance of the secondary member of the
motor or motors, and means for actuating the switches.
5. In a controller for a three-phase motor or motors, the combination of a switch
immersed in oil and arranged to make and break the primary circuit of the motor
or motors, a second switch provided with three sets of contacts engaging with as
many rows of stationary brushes and arranged to vary the resistance of the
secondary member of the motor or motors, and means for actuating the switches
simultaneously.
6. In a controller for an alternating current induction motor, the combination

page_text: of a reversing and circuit opening switch, an enclosing case in which the switch
is immersed in oil, a resistance switch arranged to simultaneously vary the resist-
ance of each of the secondary windings of the motor, and a mechanical connection
between the switches.
66
7. In an electric controller, the combination of a switch mounted for move-
ment in two directions from an off" position, means for including the switch
in operative relation to the circuit while being moved in either direction, a second
switch mounted for movement in a single direction from an off" position, and
means connecting the switches for a simultaneous operation.
66
8. In an electric controller, the combination of a reversing switch mounted for
oscillating movement in two directions from an "off" position, brushes engaging
therewith during both movements, a regulating switch mounted for oscillating
movement in a single direction from the "off" position, brushes engaging there-
with, and means connecting the switches for simultaneous operation.
9. In an electric controller, the combination of a switch mounted for move-
ment in two directions from an "off" position, means for including the switch
in operative relation to the circuit while being moved in either direction, a second
switch mounted for oscillating movement to one side of the "off" position and
operatively connected to the circuit during said movement, and a mechanical
connection between the switches for moving one of them at a greater speed than
the other.
10. In an electric controller, the combination of a reversing switch mounted for
movement in two directions from an "off" position and operatively connected
to the circuit during both movements, a resistance or regulating switch mounted
for oscillating movement on one side of the "off" position and operatively con-
nected to the circuit during said movement, and a link connecting the switches
so arranged that the relative speed of one of the switches increases as the operat-
ing devices are moved from the "off" to "full on position.
"
11. In a controller for alternating polyphase motors, the combination of a
resistance switch mounted for oscillating movement, a plurality of sets or rows
of contacts mounted on the switch, rows of stationary brushes mounted for
engagement with the rows of contacts, a switch at which the main circuit is made
and broken and a mechanical connection between the switches for imparting a
simultaneous movement thereto.
12. In a controller for a three-phase alternating current motor, the combination
. of a resistance switch mounted for oscillating movement, and comprising a three-
arm spider, contacts on the arms, three rows of stationary brushes mounted for
engagement with the corresponding rows of contacts, a reversing switch at which
the circuit is made and broken, and a mechanical connection between the switches.
13. In a controller for a three-phase electric motor, or motors, the combination
of a resistance switch arranged to vary simultaneously the resistance of the
secondary windings, a reversing switch for connecting the motor or motors to
the source of supply and reversing the direction of rotation, a mechanical con-
nection between the switches, a pinion engaging with a gear mounted on the
shaft of one of the switches, and an operating handle for the pinion.
14. In a controller, the combination of a switch cylinder mounted on a shaft,
bearings for the cylinder supported from a point above the cylinder, stationary
brushes engaging with the cylinder, and an enclosing casing in which the stationary
brushes and cylinder are submerged in oil.
15. In a controller, the combination of a switch cylinder mounted on a shaft,
a bearing for the upper end of the shaft secured to the cap plate or other fixed
portion of the controller, a lower bearing for the shaft mounted in a piece extend-
ing downward from the cap plate, stationary brushes mounted on the downwardly
extending piece and engaging with the contacts on the cylinder, an enclosing
case in which the cylinder and brushes are submerged in oil, and an operating
device for the switch.
16. In a controller, the combination of a switch, a shaft therefor, counterpart

page_text: spiders mounted thereon, each spider being provided with a plurality of arms,
the position of the spiders on the shaft being such that the arms of one spider
are displaced angularly with respect to another.
Dated the 19th. day of October, 1897.
For the Applicants.
J. C. CHAPMAN,
Chartered Patent Agent, 70, Chancery Lane, London, W.C.