Improvements in and relating to Controllers for Electric Motor Circuits and in Blow Out Magnets for Use with same.
Year: 1897

page_text: Date of Application, 8th June, 1897-Accepted, 24th July, 1897
COMPLETE SPECIFICATION.
Improvements in and relating to Controllers for Electric Motor
Circuits and in Blow Out Magnets for Use with same.
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 WILLIAM B.
POTTER, and FRANK E. CASE, both of Schenectady, County of Schenectady,
State of New York, United States of America) and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:
The present invention primarily relates to controllers for Electric motor
circuits and has for one of its objects to reduce the vertical height of the resistance
switch cylinder, at the same time maintaining the necessary insulation between
the contacts thereon. This feature of the invention is accomplished by providing
two sets of stationary brushes or contact devices adapted to engage with the
contacts carried by the resistance switch cylinder. The brushes are located
preferably at points diametrically opposite, and as the cylinder reciprocates, are
adapted to engage therewith and vary the resistance of the motor circuit.
on the
A further object of the invention consists in arranging the contacts
resistance cylinder and the stationary brushes in such relation at the making
or breaking of the circuit between them is alternately performed, first on one side
of the cylinder and then on the other; this reduces to a minimum the liability
of arcing between adjacent contact or brushes, the time interval between their
operation being double that of the ordinary construction where a single set of
bushes is employed.
A further object of the invention is to economize space; this is accomplished
by mounting the reversing switches on the base of the controller inside of the
inner periphery of the resistance switch cylinder in such a manner that the latter
is free to operate. The supports or spiders for the cylinder being located some
distance above the lower edge thereof, a sufficient amount of vertical space is
provided for the switches.
The invention further has for its object to provide a blow-out magnet simple
in construction, easy to remove for inspection or repairs, and with its energizing
coils included in separate circuits.
The invention also has for its object to provide cut-out switches in conjunction
with a controller capable of establishing more than one relation of the motor
circuits, and independently starting and controlling them while so connected.
It further provides means for preventing the actuating of the cut-out switches
except when the controlling devices are adjusted for a certain relation of the motor
circuits, and also means for. preventing the establishing of a
combination after a cut-out switch has been thrown.
new motor
A further object of the invention is to provide a certain amount of lateral
movement for the reversing and commutating switch blades so that they may
adjust themselves with relation to the stationary contacts, .but at the same time
he positively actuated in an angular direction.

page_text: The invention also relates to certain details of construction which are more
fully described and pointed out in the claims.
In the accompanying drawings, Fig. 1 is a plan of an apparatus embodying
our invention; Fig. 2 is a side elevation; Fig. 3 is a horizontal section; Fig. 4 is
a transverse section taken on the line 44 of Fig. 1; Fig. 5 is a section showing
the lower part of the controller taken on the line 5-5 of Fig. 3; Fig. 6 is an end
view of the commutating switch; Fig. 7 is a sectional view of the commutatng
and cut-out switches; Fig. 8 an end view of the blow-out magnet with the casing
in section, and Fig. 9 a diagram of connections.
In general our controller consists of a resistance switch comprising two sets of
contacts mounted on segments actuated by a common shaft and operating handle.
Located inside of the resistance switch, but independent thereof, are the reversing
switches; and a system of interlock is provided between the operating handles of
the resistance and reversing switches. Extending outward from one end of the
main case enclosing the switches, is a smaller case in which are located the
commutating and cut-out switches. A system of interlock is provided between
the commutating and resistance switches, and also between the commutating and
cut-out switches.
A is the operating lever secured to the vertical shaft A' of the resistance
switch A2 mounted at the top in a bearing carried by the top of the case B, and
at the bottom in a bearing formed by an upwardly extending portion of the
base B3 cored out in the centre to reduce the weight. As the lower bearing supports
the entire weight of the resistance switch, a ball thrust bearing B is provided
consisting of a row of balls between two hardened plates B, the upper one being
seated against a shoulder on the shaft A', the lower one resting on a portion of the
projection of the base B³. Mounted on the top of the case B is a segmental
rack B adapted to hold the lever A in any desired position by means of the
lock B².
The resistance switch A2, Fig. 3, is provided with two sets of contacts A³ and A*:
these are situated at diametrically opposite points on segments carried by the
shaft A. The segments are made of insulating material, for example, wood, and
are divided into strips A5 separated by small spaces A', which compensate for any
expansion of the insulating material. Mounted on the shaft A¹ are two
spiders C and C₁ provided with polygonal faces on their outer periphery, to which
are secured the insulating strips A5. Situated on the sides of the switch are rows
of vertically extending contact brushes D, D¹; these are adapted to vary the
resistance of the circuit as the resistance switch A² reciprocates; the contacts on
the switch and the brushes bear such a relation to each other that the circuit is
changed first at D, then at D¹, in a manner hereinafter described
Extending vertically are two square pieces of wood D2 and 13, secured at the 4
bottom to brackets E, which are bolted to the base B3 of the enclosing case, and
secured to the top by suitable means; these pieces form the supports for the cable
terminals D and their connecting brushes D³. The brushes may be of any
desired construction and are preferably provided with a certain amount of spring
to enable them to make good contact with the contacts on the resistance switch. 4
The ends of the brushes are provided with tips Do which are somewhat pointed:
these are to draw the arc to a place where it can be conveniently disrupted.
Surrounding the contact brushes are rectangular chutes E8 (Figs. 3, 5 and 8); these
restrict the direction of the arc and at the same time insulate the pole-pieces E¹
of the blow-out magnet E2 and the brushes D5.
The blow-out magnet E2 comprises a plurality of coils E³; these are mounted on
a vertically extending core E4 and are separated from one another by the
pole-pieces El and suitable insulation. The core E is secured at the top and
bottom to enlarged pole-pieces F4 (Figs. 3 and 8), the remainder being smaller,
as indicated by the dotted line H.
The blow-out magnets and are deflectors are adapted to be swung outwardly
for the purpose of inspecting the brushes or contacts on the resistance cylinder
5
5

page_text: by means of the handle E³. The brackets E which support the rectangular pieces
of wood D2, D3, are provided with projections forming lower bearings for the
vertically extending shafts F¹ and G₁ the latter are provided at the top with
bearings secured to the top of the casing. Mounted in the projecting ends of the
pole-pieces F are pins F3 and G³, the former being adapted to engage with the
arms F when it is desired to lock the blow-out magnet structure in position, and
the latter to operate as pivots when it is swung outwardly.
It is evident that the improvements in blow-out magnets which we have
invented and described, could be readily applied to forms of switches other than
the one which we have described in this case; and we aim to include such an
application of our invention in the scope of our claims. The handle E is secured
to the arm F by suitable rivets; mounted in the arm F is a pin E and engaging
therewith is a forked arm G shown in dotted lines (Fig. 3), keyed to the vertically
extending shaft G. Mounted on the upper portion of the shaft F, Fig. 8, is an
arm F engaging with the pin F and adapted when in the position shown to
prevent the blow-out magnet from moving outward. Situated between the
ple-pieces F and the top of the casing B is a fork F (Figs. 1 and 8), in which
the pin F3 travels, and by which it is guided. A similar construction is shown
on the opposite side, except that G is made in the form of a loop and forms a
centre about which the magnet is swung. I is a vertically extending cover
adapted to protect the enclosed apparatus, and is secured in any desired manner.
When it is desired to inspect the blow-out magnet and are restraining chutes.
the cover I is removed, the handle E lifted slightly releasing the lug E (Fig. 5)
from engagement with the outer frame, and a movement to the left of the handle
will cause the pin E mounted in the arm F to move toward the front and at the
same time the arm G will also be moved; the slot G6 into which the pin G³
projects is arranged to compensate for this angular movement. The lug F of
the arm F moving around the shaft F¹ as a center, will after a certain movement
release the pin F mounted on the pole-piece F; the pin G³ being in the left hand
end of the slot G2 and held from lateral movement by the arm G will act as a
center and the magnetic structure can be swung outward by hand; the arms F7
and G³ being keyed to the shafts F¹ and G2 respectively operate to move the top of
the magnet structure in a manner corresponding to the arms at the bottom.
It will be seen from the above that the magnet structure as a unit is moved
forward away from the brushes for a certain distance in a straight line before it
is moved around pins G3 as a centre; this enables the chutes Es to clear the
euds D of the brushes.
F
The reversing switches J, J, Figs. 3, 4 and 5, are mounted on wooden bases or
backs, in which the layers of wood are at right angles to each other, for the purpose
cf reducing the warping to a minimum. The switches are vertically disposed in
the controller casing and are provided with feet J2 bolted to the base 1; the
upper portions are secured by means of rods J3. On the outer surface of the bases
are mounted the binding posts J for the cable terminal; this permits the ready
inspection of the parts and reduces the complication when it is necessary to make
changes in the connections. On the inner surfaces of the bases are mounted the
stationary contact blades J; these are connected to the motors in a manner to
1 hereinafter described. The stationary contacts are provided with spring
blades J engaging with coth sides of the movable blades J7 carried by the
support JB. The latter is made of fibre or other insulating material, and secured
to its outer periphery by screws are the blades J; the centre or hub J is made of
metal and provided with a square opening through which the operating shaft. K
extends. The switches are actuated by the shaft K supported at its outer
extremities by suitable bearings in the vertical sides of the casing B and pre-
vented from lateral movement by suitable shoulders formed thereon. To permit
the switches to adjust themselves in case the shaft K gets out of line or the switch
bases out of parallel, a limited universal movement is provided for each support .JB.
The square opening in the hub Jo tapers from the centre to the outside, as shown

page_text: in Figs.
and 7; this acts as a universal joint, permitting a certain amount of
lateral movement independent of the shaft, but positively actuating the switch in
its angular movement. The switches J and J1 are so located on the base with
respect to each other and the resistance switch, that the latter surrounds the former
and is free to reciprocate as the handle A is actuated.
To guard against the simultaneous operation of me resistance and reversing
switches, an interlock is provided; mounted on the vertical shaft A¹, Figs. 3
and 4 is a cam L, and engaging therewith is a cam roller L' mounted in the end
of the arm L³. The latter has on its outer end a circular portion adapted to pass
through a bushing in the casing and engage with the hole L³, Fig. 2, in the
operating lever K₁ of the reversing switch when the latter is in the centre or
"off" position; this locks the reversing switch in such a position that the
movable blades J' are as shown by dotted lines in Fig. 5, and the circuit is
interrupted at a number of points, which guards against the accidental starting
of the car or train in the event of the motorman leaving his position.
On the operating lever K¹ is a projection K2 extending both sides of the centre,
preventing the reversing switch from being operated when the resistance switch
is in other than its off" position. The throw of the arm L2 is sufficient to cause
the end to project through the lever K¹ for locking it; the spring L is utilized
to return it to the position shown.
Mounted in an enclosing casing M forming an extension of the main case B
are the communicating and cut-out switches illustrated more particularly in
Figs. 1, 3, 6, and 7.
The
The stationary contacts N, Figs. 6 and 7, are mounted on a base or support N¹
secured to the base B3 by means of brackets N². On the back of the base are the
binding posts N³ which are connected to the motor circuits in a manner to be
hereinafter described. The bearings for the operating shaft N+ are supported
by the top of the casing M. Mounted on the shaft N is a segment N of insulat-
ing material, to which are secured the contacts No in any suitable manner.
hub of the segment No is provided with a square hole, of the same construction as
that of the reversing switches, and the switch centres itself in the same manner.
Secured to the shaft N is a lever O, Figs. 1 and 2, and connected therewith is
arod O extending upward to the lever 02 carried by the shaft which is
mounted in suitable bearings and extending laterally across the front of the con-
troller just inside of the casing, as shown in Figs. 2 and 3. Mounted on the right-
hand corner of the casing B in a suitable bearing, is a segmental bevel wheel P
engaging with a similar one 1" keyed to the shaft (3; the wheel P is formed with
a projection to which is secured the operating lever P2.
Keved to the shaft 03 directly over the lever L2 is a cam Q, Fig. 4, provided
with an opening (shown in dotted lines), into which the pin Q' is adapted to be
forced when the bell-crank lever Q2 is operated by means of the pin Q3 carried by
the arm L². The bell-crank lever Q2 is supported by a U-shaped forging bolted
to a projection on the frame of the casing B.
When it is desired to operate the communicating switch for changing the motor
connections from series to parallel or vice versa, the resistance switch is brought
to the off position, and with the reversing switch lever K' in its extreme right or
left-hand position, which will bring the operating parts to the relation shown
in the drawings; the lever 12 can be moved forward or back, depending upon
the position it previously occupied, and motion will be transmitted through the
operating mechanism to the segment N5 of the commutating switch.
event of the resistance switch being in other than its off position, the pin Q' will
have been forced upward into the hole Q or Q5 in the cam Q, and prevent the
rotation of the shaft 03. If the commutating switch is in other than its series
or parallel position, the pin Q' will engage with the outer surface of the cam Q
and movement of the resistance switch will be prevented.
In the
To provide for cutting a disabled motor or motors out of circuit and limiting
the operation of the resistance switch, separate cut-out switches are provided for

page_text: each motor, so arranged that they actuate a common limiting device when thrown
from their normal position. The cut-out switches, of which there are four, are
best shown in Figs. 1, 6, and 7; R cuts out motor M4, R¹ motor M³, R2 motor M,
and R3 motor M². The switches are provided with two blades and r pivoted
to vertical contact pieces suitably insulated from the base 133 the blades are
connected together by the insulating piece, which serves as an operating handle
tor throwing the blades into engagement with the piece S9 which connects the
blades together when a motor is cut-out of circuit.
Midway between switches R, R¹, and R3, R, are two parallel shafts S, S'; these
are mounted in suitable bearings, and keyed thereto are arms $2 engaging with
the switches when they are thrown to cut out a motor. Projecting from the left-
hand bearing of the shaft N, Fig. 7, is a lug which forms a bearing for the
spring pressed plunger S; the latter is provided with a suitable bearing at the
Lottom, and a spring S holds the disc S of the plunger in the position shown.
In the hub of the lever is a hole $7 (shown in dotted lines) into which the
plunger S is forced when a cut-out switch is thrown. Assuming, for example,
that the motors are running in multiple and trouble occurs with the motor M
the resistance switch is brought to the "off" position, the one shown in the draw-
ings, and the commutating switch thrown to the series position. The switch R
is then thrown so that the blades engage with the short-circuiting piece S9, and
the handle engaging with the lever S2 in its downward movement depressed the
latter which rotates the shaft S causing the cam $8 to engage with the under
surface of the disc S6 and raise it; the end of the plunger S is then inserted in
the hole S of the lever 0, locking the latter against further movement. In cutting
motor M2 out, the switch R would be thrown and the action of the interlock
would be the same as with motor M¹; when switch R2 or Ris thrown, the inter-
lock is operated through the medium of the shaft S and the cam S10.
The operation of the controller with respect to the cut-out switches in the
present invention differs from that of others with which we are familiar, in that
while two separate and distinct relations of the motor connections may be
established and the motors started and stopped in the usual manner while so
connected, the cut-out switches can only be operated when the motors are in the
series relation. This prevents the unbalancing of the system which would result
if one motor of a pair was cut-out, leaving its mate to be subjected to twice the
normal potential.
In this application we claim broadly a controller having a plurality of separate
means for controlling the motors with cut-out switches, which can be operated
enly when one of the said means is employed, and after the switch or switches
are thrown, cutting out a motor or motors, preventing the establishing of new
relations of the motor circuits.
Referring to Fig. 9, A3 and A represent the two segments of the rheostatic
switch A2 these are provided with horizontal rows of contacts adapted to bridge
the brushes in the rows D and D when the switch is reciprocated.
In circuit with each pair of brushes is an energizing coil of the blow-out magnet
which creates a strong field, largely local, at the point where the circuit is
interrupted and one proportional to the amount of current flowing in that par-
ticular circuit. This construction presents advantages over a single energizing
ccil for the magnet structure in that there is no waste of current consumed in
energizing a large number of contacts, but a field is created at the point where it
is most needed.
The contacts and brushes have been shown as developed on the same plane in
Fig. 9, and a movem to the left of the contact segments A3, A* with respect to
the brushes D and D will coincide with the movement indicated by the arrow
in Fig. 1.
Assuming that the switch A2 has been moved so that the contacts engage with
the rows of stationary brushes, current will enter at the trolley T, pass through
the resistance T through the coil E3 of the blow-out magnet, to the brush 2,

page_text: thence to its adjacent brush by means of the contact on A³ which spans them, to
brush 21 of row D₁ to its adjacent brush, thence by bus wire a to the cut-out
switch R2, reversing switch J, armature of M', reversing switch J, field of M',
reversing switch J, cut-out switch R2, cut-out switch R, reversing switch J',
armature of Me reversing switch J field of M cut-out switch R³,
commutating switch N7, cut-out switch R, reversing switch J, armature
of M³, reversing switch J, field of M³ cut-out switch R¹, cut-out
switch R, reversing switch J, armature of M, reversing switch J, field
of M+, cut-out switch R, to ground. This connects the four motors in series with
suitable resistance; a further movement of the switch A to the left will close the
circuit through brushes 3 and 3', then 4 and 4', which reduces the resistance of the
circuit a predetermined amount. So far the circuit has been completed simul-
taneously on both sets of contacts, but the contact opposite brush 5 on AB is slightly
in advance of the contact on A', which is opposite the brush 6, as indicated by the
dotted lines, so that the circuit is completed at 5, then 6. It will be noted that
from brush 5 in row D to brush 20 in row D₁ the circuit is alternately completed
or interrupted when returning, first on one side, then the other of the switch A²,
each step, cutting out more and more resistance; this alternation permits the gases
formed at the interrupting of a circuit to dissipate before the adjacent circuit is
interrupted, and as the contacts are arranged the time interval is double that which
it would be if a single set of brushes and contacts were employed. With the
commutating switch set as shown, the motors are connected in series and the
resistance can be cut out of or into circuit at will, forming a simple rheostatic
controller for the motors.
When it is desired to run the motors at a higher speed, the contacts No of the
commutating switch are moved to the position shown in dotted lines, which
connects the motors in series-parallel relation. The circuit enters by way of
trolley T, resistance T¹, blow-out coil E³, brush 2, thence to its adjaceut brush by
means of the contact on A³ to blow-out coil E³, to brush 21 and its adjacent brush
by means of the upper contact on A4, bus wire a, brushes 1 and 1, blow-out
coil E³, multiple brushes 4', commutating switch N7, cut-out switch R¹, reversing
switch J, armature of M³, reversing switch J, field of M³, cut-out switch R¹, cut-
out switch R, reversing switch J, armature of M, reversing switch J, field of M+,
cut-out switch R to ground. Starting back at brush 21 and bus wire a, a second
circuit is through cut-out switch R², reversing switch J¹ armature of M', reversing a
switch J¹, field of M', cut-out switch R2, cut-out switch R3, reversing switch Ji,
armature of M², reversing switch J', field of M², cut-out switch R³ to commutating
switch N to ground.
This completes the circuit of the series-parallel combination, and a further
movement of the resistance switch A2 to the left cuts out resistance until the 4
motors are connected directly between the trolley T and ground. In connection
with the brushes 4', 19, 20, 21 and 22, it will be noted that a number of them are
connected in multiple; this is to ensure good contact between the stationary and
moving parts and to carry the heavy current.
In case trouble occurs with motor M, the communicating switch N7 is brought 4
to the series position; this brings the hole S7, shown in dotted lines, in the lever O,
Fig. 7, cpposite the plunger S, and the cut-out switch R can be thrown, cutting
out motor M and locking the switch N7 in the series position. The series circuit
is now completed through the short-circuiting piece $9. The other cut-out switches
operating in the same manner, 1urther description is unnecessary.
Having now particularly described and ascertained the nature of our 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:-
5
1. In a controller for Electric Motor Circuits, the combination of a cylindrical
switch, contacts thereon, and sets of stationary brushes engaging therewith, the 5

page_text: brushes and contacts bearing such a relation to each other that the circuit is
alternately completed or broken at one set then at another.
2. In a controller, the combination of sets of contacts mounted for rotary move-
ment, sets of stationary brushes engaging therewith, one set of the moving contacts
being slightly longer or in advance of any other, whereby the interrupting or
completing of the circuits is alternately accomplished, first at one set of contacts
then at another.
3. In a controller, the combination of sets of contacts mounted for rotary move-
ment, means for imparting motion to the sets of contacts at the same rates of speed
and a plurality of rows of stationary brushes, the brushes of one row engaging
with its set of moving contacts slightly in advance of another row.
4. In a controller, the combination of two rows of stationary contacts, segments
suitably mounted for rotary movement, contacts mounted on the segments adapted
to bridge the brushes in the rows of stationary contacts, certain of the brushes
and contacts on opposite segments operating simultaneously at the closing of
the circuit, the remainder operating in alternation.
5. In a controller, the combination of switch mounted for rotary movement,
a support or spider for the switch provided with polygonal facts, strips of insulating
material secured to the faces, and contacts mounted on the insulating strips.
6. In an electric controller, the combination of a switch having stationary and
moving contacts, a second switch having a cylindrical portion enclosing the first
switch and mounted for rotary movement, the two switches being independent of
each other.
7. In a controller, the combination of a switch having stationary and moving
contacts, a vertically extending support for the switch, a second switch having a
cylindrical portion enclosing the first switch and mounted for rotary movement,
and means for operating the switches independently.
8. In a controller, the combination of a switch mounted for rotary movement,
a cylindrical portion forming a part of the switch, a spider or support for the
cylindrical portion, a reversing switch extending inside of the cylindrical portion
but independent thereof, means for operating the switches independently, and
means for preventing their simultaneous operation.
9. A blow-out magnet provided with a plurality of energizing coils, each
included in a separate circuit.
10. In a controller, the combination of a plurality of stationary contact brushes,
moving contacts engaging therewith, and a plurality of blow-out magnet coils,
each included in a separate circuit.
11. In a controller, the combination of a plurality of energizing coils mounted
on the core of a blow-out magnet, pole pieces at the ends of the core forming top
and bottom supports, and pins secured to the pole-pieces, those on one side forming
a pivot about which the blow-out magnet can be moved.
12. In a controller, the combination of a plurality of are restraining chutes,
pole-pieces between the chutes energizing coils included in separate circuits, opera-
ting shafts extending parallel with the core of the magnet, and arms connected
to the shafts for imparting similar movements to top and bottom of the magnet
structure when it is moved away from its normal position.
13. In a controller, a plurality of arc-restraining chutes, a magnet for dis-
rupting the arcs formed between contacts, an energizing coil for the magnet, a
pole-piece secured to the core of the magnet, and means for moving the magnet
and arc-restraining chutes as a unit when it is desired to inspect the operating
parts of the controller.
14. In a controller, the combination of a blow-out magnet, a handle secured
to an operating lever, a pin carried by the lever, a forked lever engaging with the
pin, vertically extending shafts to which the levers are secured, and levers mounted
at the top of the shafts engaging with the magnet structure for moving the upper
portion when the handle is pulled outward.
15. In a controller, the combination of a blow-out magnet structure, means for

page_text: moving it outward in a straight line for a certain distance, and means for pivoting
the structure on one side, so that it may be swung in the arc of a circle.
16. In a controller, the combination of a plurality of separate means for con-
trolling the motors, cut-out switches for the motors, means for preventing the
operation of the cut-out switches except when the motors bear a certain relation to
each other, and means preventing the establishing of a new relation of the motor
circuit after a cut-out switch has been thrown.
17. In a controller, the combination of a commuting switch for establish-
ing different relation of the motor circuits, a rheostatic or controlling switch in-
dependent of the commutating switch, for starting, stopping and controlling the
motors when so connected, cut-out switches for the motors, and means preventing
the operation of the switches except when the commutating switch is in a certain
position.
18. In a controller, the combination of a commutating switch for establishing,
a series or parallel relation of the motor circuits, a rheostatic or controlling switch
independent of the commutating switch, for starting stopping and controlling the
motors when so connected, cut-out switches for the motors, means for preventing
their operation except when the commutating switch is in the series position, and
means for preventing the commutating switch from establishing a new relation of
the motor circuits after a cut-out switch has been thrown.
19. In a switch, the combination of fixed contacts, a plurality of moving con-
tacts engaging therewith, an insulating support to which the moving contacts
are secured, an actuating shaft, and means permitting the insulating support to
rock on the actuating shaft.
20. In a switch, the combination of fixed contacts, a plurality of moving con-
tacts engaging therewith, an insulating support to which the moving contacts are
secured, and a metal hub for the support so arranged that a limited lateral move-
ment of the insulating support is permitted independent of the shaft, but which
is positively actuated in an angular direction.
21, In a controller, the combination of parallel switches, stationary contacts
therefor, an operating shaft, movable contacts, supports for the contacts mounted
on the shaft, and means for providing a certain amount of lateral movement to
tach supported independent of the other or others.
22. In an electric controller, the combination of contacts mounted for rotary
movement in a horizontal plane, and contacts mounted for rotary movement in
a vertical plane, first set of contacts being mounted inside of the other, and means
for actuating both sets of contacts independently.
Dated this 8th day of June. 1897.