US1405493A - Motor controller - Google Patents

Description

A. J. CLINE.

MOTOR CONTROLLER. AP-PLICATION FILED DEC.30, 191's.

Patented Feb. 7, 1922.

javezaZE'r 4404 few UNITED STATES PATENT OFFICE.

ALLAN J. CLINE, OF CHICAGO, ILLINOIS.

MOTOR ooN'rRoLLER.

by which the operator can stop and start the motor as desired and control the different motor speeds, together with devlces automatically operating in accordance with conditions established in the motor circuit for protecting the motor and controlling its rate of acceleration. A further object of the invention is to provide an arrangement in which the switch contacts and parts that directly control the armature circuit can be located at a main controller station and the speed A regulating and auxiliary control switches at a distant sta-.

' tion or stations, and in which arrangement it is only necessary to connect small, light -wires to the control station or stations so that the latter can be light in construction andconveniently mounted on the machine within easy reach of the operator.

The conductors 10 and 11 of the supply circuit for the motor are -connected to the mains 12 by a line switch 13. The switches and other parts which carry the armature current are located at the main station A and the manually operable control switches are located at another station or stations B and B.

The main controller station comprises a resistance 14 for the circuit of the armature Specification of Letters Patent.

Application filed December 30, 1918. I Serial No.

Patented Feb. '7, 1922.

A, separate electro-magnetic starting and reversing switches 15 and 16, which are provided with normally engaged and disengaged contacts and which operate to start and reverse the motor and a series of electro magnetic resistance switches 17, 18 and 19 which are arranged to cut out successive portions of the armature resistance 14. The main station is also provided with a relay 20 the coil of which is interposed in the armature circuit and which if excessive current flows through the armature circuit, is arranged to short circuit the field resistance.

The positive supply conductor 10 in the arrangement shown is connected in parallel to the normally engaged or down contacts 21 ancl 22 of the, starting and reversing switches 15 and 16. The negative supply conductor 11 is connected to one terminal of the armature resistance 14, the other terminal of which is connected in parallel, by conductors 23 and 24, to the normally disengaged or up contacts 25 and 26 of the starting and reversing switches. If desired, the normally disengaged contact 26 of the reversing switch may be connected by conductor 24 to some other point of the main resistance 14. The armature terminals are connected respectively to the movable contacts of the starting and reversing switches by the conductors 27 and 28, the coil of the relay 20 being interposed in the conductor 27. Preferably, as shown, a brake resistance 29 is interposed between the normally engaged or down contacts of the starting and reversing switches. a

When the starting switch 15 is energized, the motor circuit can be traced from the conductor 10, contact 22 of the reversing switch, by conductor 28 through the armature A, thence by conductor .27 through the coil of the relay 20 and the up contact 25 of the starting switch, thence by conductor 23 through the armature resistance 14 to the negative supply conductor 11. When the reversing switch is operated, the motor circuit is traced from positive conductor 10 through the brake resistance 29 to the down contact 21 of the starting switch and conductor 27' through the armature A, thence by conductor 28 to the normally disengaged or up contact 26 of the reversing switch and by conductors 24 and 23 through the armature resistance to the negative conductor 11. When the operation of the motor is stopped, a circuit is formed from its positive terminal through conductor 28, down contact 22 of the reversing switch 16,

' through the brake resistance 29 and down the usual manner to cut out different sections of the armature resistance but, in the arrangement shown, these switches are only brought into operation when the motor is running in a normal direction.

The main controller station is also provided with a relay having normally open contacts 31 and 32 which are interposed re- "spectively in the energizing circuits for the starting switch 15 and for the resistance switches 17, 18 and 19.

The controlling station B comprises a master control or speed regulating switch arm 33 of conducting material pivoted between its ends and arranged to engage and supply current to a number of contact buttons and segments. The movement of the switch arm in opposite directions is limited by a fixed stop 34 and in one direction b a pivoted or movable stop 35. Current is supplied for the control circuit from the positive conductor 10 of the main circuit by a conductor 36 which is always in electrical connection with the master control or speed regulating switch arm 33 through the medium of a contact se ment 37. In the normal or idle position of e master control switch, it engages the movable stop and dead contacts 38 and 39. As the switch is shifted in right hand direction, it successively engages two contact buttons 40 and 41 which supply current to the relay 30. As the switch is further shifted in right hand direction, it is disengaged from the contact button.41 and engages a segment 42 which supplies current to a holding circuit for relay 30 and to'the starting switch 15 during further forward movement of the arm. After energizing the starting switch 15, the switch arm is arranged to successively engage two contact buttons 43' and 44 and a contact segment-45 which are respectively connected to the coils of the resistance switches 17, 18 and 19 which control the acceleration of the motor to what may be termed normal running speed. During the movement of the main controlling switch thus far described, it is in engagement with a contact segment 46 which supplies current to the shunt field F of the motor. After engaging the contact segment 45, the switch arm can be disengaged from the segment 46 and arranged to cooperate with the contacts of a field resistance 47 to further accelerate the motor speed. By shifting the movable stop 35, the master control switch can be moved from normal or idle position in left hand direction into engagement with a contact button 48 which supplies current to the reversing switch 16.

Auxiliary control or push button switches are also provided, either at the control station B or at another control station or stations B. Preferably, as shown, the auxiliary control station comprises a spring held push button switch 49 having normally en aged contacts interposed in the circuit for ho ding the relay 30 in operated condition and for energizing the starting switch 15 and two spring held push button switches 50 and 51 having normally open contacts which are arranged to supply current respectively to the relay 30 for running, and to the starting switch 15 independently of the relay, for inching. lreferably, the push button switch 50 is provided with a pair of normally closed contacts which are interposed in the energizin circuit of the auxiliary or resistance switches 17, 18 and 19, and the switch button is provided with a projecting lug 52 which may be moved through a notch in a stationary holding glate 53 and then, by partially rotating the utton, the latter may be held out of engagement with its normally engaged contacts.

The push button station is also preferably provided with a switch comprising two sets of normally closed contacts 54 and 55 which circuit 0 the starting relay and the feed conductor to the push button switches 50 and 51. v

The movable members of the sets of contacts 54 and 55 are preferably each provided with a push button and are connected by an oscillating member 56 which is plvoted between its ends so that when one button is depressed the other is raised. A spring 57 cooperates with the member 56 to hold the cont-acts either open or closed.

The master control or speed reguatmg switch 33 in idle position engages the contact segment 46 so that when the line switch 13 is closed a circuit is closed through the shunt field from the positive conductor 10, by conductor 36, segment 37, switch arm 33, segment 46, conductor 58 through field F and by conductor 58' to the negative main 11. The segment 46 is of such length that the switch arm remains in engagement theretacts 31 and 32. When the switch arm I ductor 59 is interposed in the circuit of the relay 30- and somewhat reduces the flow of current therethrough but the latter still holds its contacts 31 and 32 closed. When the switch arm engages the segment 42, a circuit can be traced therefrom through a conductor 61in which the normally closed push button contacts 54 and 49 are included to the relay contacts 31 and then by conductor 62 and contacts 64 through the energizing coil of the starting switch 15 to the negative main 11. The conductor 61 is connected to the conductor 59 by a resistance 63 so that, with the switch arm 33 in engagement with the segment 42, a holding circuit is closed from conductor 61 through resistance 63, conductor 59 and coil of relay 30. The contacts of the latter are thus held closed, the movable contact of the starting switch is engaged with its fixed contact 25 and the armature circuit is closed through the resistance 14, so that the motor will then start and continue in operation at slow speed. The starting switch is preferably provided with normally closed contacts 64 interposed in its energizing circuit and in shunt to a protective resistance 65. When the switch is operated, the contacts 64 are opened and the protective resistance 65 is introduced into its energizing circuit to reduce the flow of current through its coil. As the control switch arm 33 is moved over the contacts 40 and 41, it connects the conductor 59 to the positive supply main and energizes the relay 30, as described, to close contacts 31 in the energizing circuit of the starting relay, but on account of the resistances 63 and 60, suflicient current will not flow through the contacts 31 to operate the starting switch until the switch arm engages the segment 42 and thereby closes the energizing circuit of the starting switch around the resistances 63 and 60.

After the motor is thus started to operate at slow speed, it cambe further accelerated by shifting the switch arm to successively engage the contacts 43, 44 and 45 to close the circuits of the accelerating or resistance switches 17, 18 and 19. The coils of these switches are interposed between the positive supply conductor-10 and the negative pole of the motor and are thus energized by the counter electromotive force developed by the They are also so arranged that, when in circuit, these coils will operate suc-.

motor.

cessively to reduce the resistance in the armature circuit as the motor accelerates and reaches difierent predetermined speeds. Thus, while the running speed is determined by the position of the manually operable controlling switch arm 33, the rate of acceleration is automatically controlled in accordance with the load on the motor.

'The coils of the resistance switches are preferably arranged in series and each switch, except the last to operate-that is to say, the resistance switches 17 or 18, are provided with normally closed contacts 66 and 67 which serve, respectively, to close shunts around the coils of the succeeding switches 18 and '19. The resistance switch 19, which is thelast to operate, is also provided with contacts 68 which in normal or idle condition close a shunt around a resistance 69 which is interposed in the energizing circuit of the resistance switches.

When the controlling switch arm is in engagement with the contact 43, a circuit can be traced therefrom by a conductor 70, conductor 71 leading through the contacts 32 of the relay'30 and the upper contacts of the push button switch 50, thence through the coil of the first resistance switch 17 and by conductor 23, contact 25, which is then engaged by the movable contact of the starting switch, and conductor 27 to the negative pole of the armature. Then, when suflicient counter electromotive force is developed in the armature circuit, the switch 17 is operated to cut out a portion of the armature resistance and open the contact 66 and the shunt around the coil of the resistance switch 18. When the switch arm 33 engages the contact 44 and when the first resistance switch 17 has been operated, a circuit may be traced from the controlling switch arm 33, contact 44, conductor 72 through the coil of the switch 18 and thence by conductors 73 and 71, through the coil of the first resistance switch 17 and back as before to the negative pole of the armature. When the controlling switch arm 33 engages the contact segment 45 and after the first and second resistance switches have been operated, a circuit is closed from the switch arm by contact 45, conductor 74, contacts 68, through the coil of the resistance switch 19 by conductor 75, through the coil of the resistance switch 18, conductors 73 and 71 to the coil of the first resistance switch 17 and back as before to the negative pole of the armature. When the last resistance switch 19 is operated, it opens the contact 68 and introduces the protective resistance 69 into the energizing circuit of the coils of the rement 45; When this occurs, the current'is traced from segment 45 by conductor 74,

- contacts 68, 67 and 66 and conductors 73 and 71 through the coil of switch 17. When switch 17 operates, it opens contacts 66 and includes the coil of switch 18 in the circuit and the operation of the latter opens the shunt contacts 67' around the coil of switch 19. While the circuits of the resistance switches are thus closed by the control switches and shunt contacts 66 and 67, they are responsive only to different conditions established in the armature circuit and ate the motor. If the reduction of the field current causes an excessive flow of current in the armature circuit, the field relay 20 operates to close the contacts and thereby close a shunt around the field resistance. The field circuit is then closed from positive conductor 10, by a conductor 76, field relay contacts, conductors 77 and 58, through the vfield F and by conductor 58' back to the negative supply main. This rel-ay is arranged to close andopen the shunt around the field resistance repeatedly until proper conditions are established in the motor circuit. The controlling switch arm 33 canbe quickly shifted to any one of its running positions to determine any oneof a number of different speeds by cooperation with the armature resistance switches 17, 18 and '19 and the field resistance '47, but the motor circuit is automatically protected, since conditions-established therein control the rate of acceleration efi'ected bythe switches 17 18' and 19 and the operation of the full field relay 20. Obviously, the controlling switch arm 33 can be shifted from any of its running positions to reduce the field resistance and successively open the circuits of resistance switches 19, 18 and 17 starting switch 15 and relay 30 to decelerate the motor as required or to stop the motor.

In any of the running positions of the master control or speed regulating switch 33, the motor can be stopped by depressing the push-buton 49 to open the conductor 61 and de-energize the holding circuit of the relay 30 and the energizing circuit of the starting switch 15. The release of the stop pushbutton 49 closes its contacts in the conductors 61, but resistance 63 prevents energizat-ion of the relay 30 so that the relay contacts-31 in the circuit of the starting switch remain open. The motor can then be started by depressing the push-button 50 to close a circuit from the supply conductor 36, by a conductor 78, normally engaged contacts 55, conductor 79, through the lower contacts of the push-button switch 50 and thence by the conductors 80 and 59 through the coil of relay 30. The latter then operates to engage contacts 31 and, since the conductor 61 is then connected by the speed controlling switch 33 to supply conductor 36, the holding circuit of the relay 30 through the resistance 63 and the energizing circuit of the starting switch are re-established. The latter then closes the armature circuit and starts the motor for continuous operation.

The operation of relay 30 also engages its contacts 32 and the release of the push-button 50 connects its'upper contacts so that the circuit of the resistance switches is closed at these points and the motor will automatically accelerate to a speed determined by the position of the master control or speed regulating switch arm 33. Thus, in any of the running positions of the switch arm 33, the stop and run buttons-49 and 50 can be depressed and released to stop and again start the motor and effect its acceleration to any one of a number of different speeds, the rate of acceleration, as noted before, being controlled automatically in acordance with conditions established 1n the motor circuit and the load on the motor.

After the motor is stopped it can be started for continuous operation at slow speed in any of the running positions of the main control switch, by depressing the run button 50 and partially rotating it so that, when released, the lug 54 thereon will engage the holding plate 53. This operation will energize relay 30 and starting switch 15 as described but will not close the circuit of the accelerating switches. In any position, and independently of the master control switch, the motor, when stopped, can be started for limited running by depressing the inch pushbutton switch 51. A circuit is then closed through conductors 36, 7 8, 7 9, the contacts of the inch but-ton, conductors 81 and 62, contacts 64 and the coil of the starting switch 15. This circuit is closed independently of the relay 30, so that the starting switch only remains energized as long as the inch button is held depressed. The contacts 55 are interposed in the feed conductors 78 and 79 for the run and inch buttons and the contacts 54 are interposed in the conductor 61 which supplies current to the holding circuit of the relay 30 and to the energizing circuit of the starting switch. By depressing the safe button, contacts 54 and 55 are opened so that the motor cannot be started either by the main control switch or by the auxiliary push-button switches until the on button is depressed to again close these contacts.

In any of the running positions of the main control switch, the motor can be stopped, as stated, by depressing the .pushbutton switch 49. Means are provided for then preventing the starting of the motor by the return of the main control switch to normal or idle position. If, as the switch is returned it could simultaneously engage the segment contact 42 and the contact button 40, it would energize both the relay 30 and the starting switch 15 and thus start the motor,

but since the additional contact 41 and resistance are interposed between the contacts 40 and 42, the return movement of the switch cannot energize the relay 30 until it is entirely'disengaged from the segment contact 42. .While the additional contact 41 and resistance 60 thus prevent starting under the circumstances noted, they also serve to hold the relay 30 energized when the control switch 33 is moved forward from contact 40 to contact 42, resistance 63 being in sufiicient to de-energize the relay after it has operated. I

With the controlling switch arm 33 in normal position, it can be shifted in left hand direction, after releasing the shiftable stop 35, to engage the contact 48. A circuit is then closed from contact 48 by conductor 82 through the coil of the reversing switch and the conductor 83 to the negative supply controller station A, and the contacts of the controlling circuit are of the same polarity, so that the manually operable speed regulating and controlling switches and the wiring therefor can be of a light construction and co'nvenientl located on the press or other machine driven by the motor. The operator has full control of the running speed of the motor and can quickly and readily change the same or start and stop the motor for limited or continuous running at slow speed or for continuous running at any one of a number of different speeds, but under all conditions the acceleration of the motor is automatically controlled by conditions established in the armature circuit.

Obviously, the manually operable main and auxiliary control switches may be located at the same or at a number of different stat-ions, as desired. Other changes maybe made in the details of construction and the arrangement of the circuits set forth, without departure from the essentials of the invention as defined by the claims.

I claim as my invention 1. In combination in a motor controller, electro-Inag'netio starting means, electromagnetic accelerating means automatically responsive to difi'er'ent electric conditions established inthe motor circuit, a speed control switch arranged to variably limit the operation of said accelerating means and thereby determine the running speed of the motor, and auxiliary control push-button switches operable to stop and start the motor.

2. In combination in a motorcontroller, electro-magnetic starting means, electromagnetic accelerating means automatically responsive to different electric conditions established in the motor circuit, a speed control switch arranged to variably limit the operation of said accelerating means and speed of the thereby determine the running n} push-butt'o motor, and auxiliary contro switches one operable to de-energize said starting and accelerating means and the other operable to energize said starting means and variably control said accelerating means in accordance with the setting of said speed control switch and thereby start the motor and effect automatic acceleration thereof in accordance with the load to any one of a number of different predetermined speeds.

3. In combination in a motor controller, electro-magnetic -starting means, electromagnetic accelerating means automatically responsive to diiferent electric conditions established in the motor circuit, a eed control switch arranged to variably imit the operation of said accelerating means and thereby determine the running speed of the motor, and auxiliary control push-button switches operable to stop the motor and start the same for limited operation at slow speed or for continuous operation at a speed determined by the setting of said speed control switch.

4. In combination in a motor controller, electro-magnetic starting means, electromagnetic accelerating means automatically responsive to difierent electric conditions established in the motor circuit, a speed control switch arranged to variably limit the operation of said accelerating means and thereby determine the running speed of the motor, and auxiliary control, push-button switches, one'operable to stop the motor andanother operable to start the motor for continuous operation at slow speed or at a speed determined by the setting of said speed control switch.

5. In combination in a motor controller, an electro-ma'gnetic starting switch, a series of electro-magnetic resistance switches responsive successively, when in circuit, to different conditions established in the motor circuit, a speed control switch for directing the operation of one or more of said resistanoe switches to thereby predetermine the running speed of the motor, and sets of auxiliary control contacts, one set operable to de-energize said starting and resistance switches and another operable to energize said starting switch and variably control said resistance switches in accordance with the setting of said speed control switch.

6. In combination in a motor controller, an electro-magnetic starting switch, a series of electro-magnetic resistance switches responsive successively, when in circuit, to different conditions established in the motor circuit, a speed control switch for directing the operation of one or more of said resistance switches to thereby predetermine the running speed of the motor, and auxiliary control contacts operable to tie-energize said starting and resistance switches for stopping and to energize the same or said starting switch only for running at the predetermined speed or at slow speed.

7. In combination in a motor controller, an electro-magnetio starting switch, a series of electro-magnetic resistance switches responsive successively, when in circuit, to difierent conditions established in the motor circuit, a speed control switch for directing the operation of one or more of said resistances switches to thereby predetermine the running speed of the motor, and auxiliary control push-button switches operable to deenergize said starting and resistance switches for stopping and to variably control the same 4 for continuous or limited running at slow speed or for continuous running at the predetermined speed.

8. In combination in a motor controller, electro-magnetic starting and accelerating means, a master control switch manually operable to start and stop the motor and effect acceleration thereof to any one of a number of different speeds and auxiliary control push-button switches operable in any of the run positions of said master switch to stop the motor and start the same for running at a speed determined by the position of said master switch.

9. In combination in a motor controller, electro-magnetic starting and accelerating means, a master control switch manually operable to start and stop the motor and effect acceleration thereof to any one of a number of difierent speeds and auxiliary control push-button switches,one operable to stop the motor and another operable to start the same for continuous running at slow speed or at a speed determined by the position of said master switch.

10. In combination in a motor controller, electro-magnetic starting and accelerating means, a master control switch manually operable to start and stop the motor and efl'ect acceleration thereof to any one of a number of different speeds and auxiliary control push-button switches operable to stop the motor and start the same for limited running at slow speed or continuous running at a speed determined by the position of said master switch.

11. In combination in a motor controller, an electro-magnetic starting switch, a series of electro-magnetic resistance switches, a master control switch manually operable to energize the circuit of said starting switch and thereafter successively close the circuits of said resistance switches, said resistance switches being responsive automatically and successively as different electrical conditions are established in the motor circuit, and auxiliary control push-button switchesoperable, in any of the running positions of the master switch, to de-energize said starting and resistance switches to stop the motor and to variably control the same to start the motor for operation at slow speed or at the speed determined by the position of said master switch.

12. In combination in a motor controller, armature and field resistances, an electromagnetic starting switch, a series of electromagnetic switches for successively cutting out sections of said armature resistance, a relay for short circuiting said field resistance, said resistance switches and said field relay being automatically responsive to electrical conditions established in the armature circuit, manually operable speed control contacts cooperating with said resistance switches and said field resistance to determine the running speed of the motor, and

auxiliary manual control contacts operable to stop the motor and again start the same for operation at a speed determined by the setting of said speed control contacts.

13. In combination in a motor controller, armature and field resistances, an electromagnetic starting switch, a series of electromagnetic switches for successively cutting out sections of said armature resistance, a relay for short circuiting said field resistance, said resistance switches and said field relay being automatically responsive to electrical conditions established in the armature circuit, a manually operable speed control switch having a series of contacts connected to the circuits of said resistance switches and to the sections of said field resistance and cooperating therewith to determine the running speed, and an auxiliary control pushbutton switch operable to stop and start the motor for operation at slow speed or at a speed determined by the position of said speed control switch.

14:. In combination in a motor controller, an electro-magnetic starting switch, a series of electro-magneticresistance switches automatically and successively responsive, when in circuit, to different conditions established in the motor circuit, and push-button control switches, one operable to open the circuits of said starting and resistance switches, another operable to close said circuits and a third operable to close the circuit of said starting switch alone.

15. In combination in a motor controller, an electro-magnetic starting switch, aseries of electro-magnetic resistance switches automatically and successively responsive, when in circuit, to different conditions established in the motor circuit, a relay having contacts in the circuits of said starting and resistance switches, and push-button control switches operable to open and close the circuit of said relay or to close the circuit of said starting switch independently of said relay.

16. In combination in a motor controller, an e'lectro-magnetic starting switch, a series of electro-magnetic resistance switches automatically and successively responsive, when in circuit, to different conditions established in the motor circuit, a relay having contacts in the circuits of said starting and resistance switches, a master control switch manually operable to close and open the circuits of said relay and said starting switch and cooperate with said resistance switches to determine the running speed of the motor, and auxiliary control push-button switches for opening and closing the circuit of said relay and for closing and opening the circuit of said starting switch independently of said relay.

17. In combination in a motor controller, a

an electro-magnetic starting switch, a series of electro-magnetic resistance switches automatically and successively responsive, when in circuit, to different conditions established in the motor circuit, a relay having contacts for opening and closing the circuits of said starting and resistance switches and manually operable control contacts for variably controlling the circuits of said relay and of said starting switch to stop the motor and start the same for limited or continuous running.

18. In combination in a motor controller, an electro-magnetic starting switch, a series of electro-magnetic resistance switches automatically and successively responsive,'when in circuit, to different conditions established in the motor circuit,- a relay having contacts in the circuits of said starting and resistance switches and separate manually operable speed regulating and controlling switches arranged to variably control the circuits of said relay and of said starting and resistance switches to start and stop the motor and effect limited running thereof at one speed or continuous running at any one of a number of different speeds.

19. In combination in a motor controller, electro -ma netic s arting means, electromagnetic accelerating means, a master control switch arranged to successively cooperate with said starting and accelerating means to start the motor and effect acceleration thereof to any one of a number of different speeds, an auxiliary push-button switch operable in any of the run positions of said master switch to stop the motor, and

returned to idle position after the stopping of the motor.

21. In combination in a motor controller, an electro-magnetic starting switch, an electro-magnetic accelerating switch, a relay' having contacts in the circuits of said starting and accelerating switches, a master control switch having a series of contacts adapted to successively close the circuits of said relay, said starting switch and said accelerating switch, and auxiliary control contacts for opening and closing the circuit of said relay to stop and start the motor.

22. In combination in a motor controller,

an electro-magnetic starting switch, an electro-magnetic accelerating switch, a relay having contacts in the circuits of said starting and accelerating switches, a master control switch having a series of contacts adapted to successively close the circuits of said relay, said starting switch and said accelerating switch, auxiliary control push-button switches for opening and closing the circuit of said relay to stop and start the motor, and an additional contact and a resistance interposed between the relay and starting switch contacts of said master switch for preventing energization of said starting switch as said master switch is returned to idle position after stopping of the motor.

23. In combination in a motor controller, an electro-magnetic starting switch, an electro-magnetic accelerating switch, a relay having contacts in the circuits of said starting and accelerating switch, a master control switch having a series of contacts adapted to successively close the circuits of said relay, said starting switch and said accelerating switch, a resistance interposed between the circuits of said relay and said starting switch and constituting part of aholding tween the relay and. starting switch contacts, a resistance interposed between said additional contact and the circuit of said relay, and an auxiliary control push-button switch for opening the holding circuit of said relay.

24. In combination in a motor controller, electro-magnetic starting and accelerating means, a master control switch normally 0perable to start and stop the motor and effect its acceleration to any one of a number of different speeds, and auxiliary control pushbutton switches, certain of which are operable for starting and stopping and another adapted to be set in position to prevent starting either by said master switch or by the starting push-button.

25. In combination in a motor controller, separate electro-magnetic starting and reversing switches having normally engaged and disengaged contacts and arranged to cooperate to start and reverse the motor, electro-magnetic accelerating means automatically responsive, when in circuit, to conditions established in the motor circuit, and a master control switch having contacts for separately closing the circuits of said starting and reversing switches and a series of contacts for controlling the operation of said accelerating means.

26. In combination in a motor controller, separate electro-magnetic starting and reversing switches having normally engaged and disengaged contacts and arranged to cooperate to start and reverse the motor, electro-magnetic accelerating means auto matically responsive, when in circuit, to conditions established in the motor circuit, a master control switch having contacts for separately closing the circuits of said starting and reversing switches and a series of contacts for controlling the H operation of said accelerating means, an auxiliary pushbutton switch for opening the circuit of said starting switch and said accelerating means to stop the motor, and a brake resistance interposed between the normally engaged contacts of said starting and reversing switches. 27. In combination in a motor controller, armature and field resistances, an electromagnetic starting switch, electro-magnetic accelerating switch mechanism responsive automatically to conditions established in the motor circuit for controlling said armature resistance, a relay responsive to abnormal conditions in the motor circuit for short circuiting said field resistance, said starting switch being arranged to close the circuit of said relay independently of said accelerating switch mechanism, and manually operable contacts for controlling said starting switch, said accelerating switch mechanism and said field resistance to effect the operation of the motor at any one of a number of difierent speeds.

28. In combination in a motor controller,

a series of successively operating electromagnetic resistance switches having their coils connected in series, and manually operable speed-regulating contacts for successively closing the circuits of said switches,

each resistance switch, except the last to operate, being arranged in operating to open a short circuit around the coil of the succeeding switch.

29. In combination in a motor controller, a series of successively operating electromagnetic resistance switches having their coils connected in series, a manually operable, speed regulating switch having a series of contacts for successively closing the circuits of said switches, each resistance switch, except the last to operate, being arranged in operating to open a short circuit around the coil of the succeeding switch, and means controlled by the complete operation of said switches for reducing the flow of current through the coils thereof.

30. In a motor controller, the combination of controlled and controlling circuits, an electro-magnetic starting switch and one or more electro-magnetic accelerating switches having contacts in the controlled circuit and energizing coils in the controlling circuit, said accelerating switch or switches being responsive to predetermined conditions established in the motor circuit, a manually operable switch in the controlling circuit for directing the Operation of said accelerating switch or switches and thereby predetermine the running speed of the motor, and auxiliary switches in the controlling circuit manually operable tostart the motor for operation at the predetermined speed or at slow speed, and to stop the motor.

31. In a motor controller, the combination with controlled and controlling circuits, of a main station comprising an electro-magnetic starting switch and one ormore electromagnetic resistance switches, said starting and resistance switches having contacts in the controlled circuit and energizing coils in .the controlling circuit, and a controlling station comprising switch contacts in said controlling circuit for governing the operation of said resistance switch or switches,

and push button switches in said controlling circuit operable to start the motor for limited operation at one speed or for continuous operation at different speeds, and to stop the motor.

32. In a motor controller, an electromagnetic starting switch, one on more electro-magnetic resistance switches responsive to predetermined conditions established in the motor circuit, energizing and holding circuits for said electro-magnetic starting and resistance switches, and sets of manually operable switch contacts for variably controlling said energizing and holding circuits to start and stop the motor and efl'ect the limited operation thereof at one speed or continuous operation at different speeds.

33. In a motor controller, an electromagnetic starting switch, one or more elect-ro-magnetic resistance switches responsive to predetermined conditions established- 1n the motor circuit, relay means having separate sets of contacts interposed respectively in the energizing circuits of said starting and said resistance switches, a switch aving contacts in the energizing circuit of said resistance switch or switches and manually operable to predetermine the motor speed, and push button switches for variably controlling the circuits of 'saidstartin switch and said relay and operable to start the motor for limited operation or for continuous operation at different speeds, and to sto the motor.

34. a motor controller, the combination with controlled and controlling circuits, of an electroamagnfetic starting switch, an electro-magnetic reversing switch and an electro-maginetic accelerating switch or switches, said electro-magnetic switches having contacts in the controlled circuit and energizing coils in the controlling circuit, and separatemanually operable switches having contacts in the controlling circuit arranged to variably control said electromagnetic switches to start the motor for forward operation at difl'erent speeds, stop the motor and reverse the same.

35. In a motor controller, the combination with a motor circuit and a controlling circuit, of a series of electro-magnetic resistance switches having coils connected in series in the controlling circuit and arranged to respond automatically and successively to conditions established in the motor circuit, and a manually operable, speed regulating switch in the controlling circuit for determining the operation of one or more of said resistance switches, each resistance switch, except the last to operate, being arranged to open a short circuit around the coil of the succeeding switch.

36. In combination in a motor controller, separate electro-magnetic starting and reversing switches, each having a movable contact and normally engaged and disengaged relatively fixed contacts and said g switches being arranged, when either one is operated, to supply current to the motor through the normally engaged contact of one switch and the normally disengaged contact of the other switch, and manually operable contacts for separately controlling the energizing circuits of said electromagnetic starting and reversing switches.

37. In combination in a motor controller, separate electro-magnetic starting and reversing switches, each having a movable contact and normally engaged and disengaged relatively fixed contacts, current supply conductors, one connected to the normally engaged contacts of said starting and reverslng switches and; the other to the normally disengaged contacts of said switches, a motor having its terminals connected to the movable contacts of said switches, a brake resistance interposed between the normally engaged contacts of said switches, and controlled contacts for separately energizing the circuits of said switches.

ALLAN J. CLINE.

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