US1031650A - Starting-switch for electric motors. - Google Patents

Description

O.'D. KNIGHT.

STARTING SWITCH FOR ELECTRIC MOTORS.

APPLIUATION FILED DEC. 1, 1905.

Patented. July 2, 1912.

2 SHEETS-SHEET 1.

lNvENTuR- CHARLES UKNiBHT.

G. D. KNIGHT.

STARTING SWITCH FOR ELECTRIC MOTORS.

APPLICATION FILED 1930.1,1905.

1,031,650. Patented July 2,1912.

2 SHEETS-SHEET 2.

' \A/iTNI-ISSES. lNvE NTDR- flKQQ J75 CHARLES D. KNIGHT.

MW W

Atoq- UNITED STATES PATENT OFFICE.

CHARLES 1).. KNIGHT, OF SCHENECTAD'Y, NEW YORK ASSIGNOR- TO GENERAL ELECTRIC COMPANY, A CORPORATION .OF NEW YORK.

, STARTING-SWITCH EOR ELECTRIC MOTORS.

To all whom it may concern:

Be it known that I, CHARLES D. KNIGHT,

a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Starting-Switches for Electric Motors, of which the following is a specification.

My invent-ion relates to starting switches for electric motors, and is particularly adapted for use with alternating-current motors of the type which are cont-rolled by connecting them to a source of low voltage for starting and then increasing the impressed voltage for running. But my invention is not limited to this particular type of motor.

The object of my invent-ion is to provide a simple, efficient and reliable automatic starter for electric motors, by means of which motors may be controlled from a distance either manually or by automatic switching devices, such as pressure governors, float switches, etc.

My invention in one aspect consists in the combination with an electric motor, of two switches for establishing respectively starting and running connection, operating magnet-s for the switches, and means controlled by the operating magnet of the starting switch for energizing the operating magnet of the running switch at a predetermined interval after the first magnet is energized. In another aspect my invention consists in the combination with an electric motor, of two switches adapted to establish respectively startingand running connections, a control system comprising automatic operating means for said switches adapted to close the starting switch, andthen to close the running switch and open the starting switch after a predetermined interval, and

means for deenergizing the operating means when the running switch is closed.

In still another aspect my invention consists in the combination of an alternating current motor and an alternating current;

supply circuit of a transformer anda plurality of automatically operated switches Specification of Letters Patent.

' Patented July 2, 1912.

Application filed December 1, 1905. Serial No. 289,774.

for first connecting the motor to the supply circuit through the transformer and then connecting the motor directly to the supply circuit.

My invention further comprises a number of other featurih, which will best be understood by reference to the accompany ing drawings, in which Figure 1 shows a front elevation, partly in cross-section, of an automatic motor starting switch in accordance with my invention; and Fig. 2 is a diagram showing, the circuit connections.

Referring first to Fig. l, 1 and 2 represent two knife-blade switches adapted to establish respectively the proper connections for starting and for running. The switch 1 is operated by the magnet 3 through a rod 4: which is connected to the switch, and which, when the switch is opened, hold the switch in the position shown by means of a button 5 at the upper end of the rod engaging the top of the magnet. 6 repre sents the core of the magnet which, when drawn up, engages and lifts the collar 7 on the rod 4, thereby closing the switch 1. When the rod 4 is thus raised the button 5 on the upper end of the rod engages the switch contact 10 in circuit with the magnet 3. The upper end'of the core 6 is formed as a piston moving within the bore of the magnet 3, and by means of the passages 9 and the ball valves 8, a dash-pot construction is provided which permits'the free upward movement of the core while retarding its downward movement. The core 6 carries a cont-act 11, which in certain positions of the rod and core, as will hereinafter be explained, engages the contacts 12 carried by the rod 1. The running switch 2 is operated by a magnet 13, and is provided witha lug 14 adapted to engage switch 1 when switch 2 is closed and to force switch 1 open. The two switches are thus mechanically interlocked. The core of magnet 13 is connected to the switch 2 by a lost-inotion connection, as shown. This lost-motion connection enables the core of magnet 13 to impart a hammer-blow to the switch of which is a button 15 which,'like the button 5, is adapted to engage the contact 10. 16 is a spring-actuated latch controlled by. a no-voltage release magnet 17. When the.

- magnet 17 is energized and the magnet 13 draws up its core the latch' 16 is forced by its spring into engagement withfa notch on t the spindle 23 carried by the core of magnet 13, so as to hold the'core in its raised position.

Now, referring to Fig. 2, the circuit conne'ct-ions and mode of operation will be explained M represents an electric motor which in this figure is indicated as a threephase induction motor and which is connected by switches 1 and 2 either to intermediate points on the winding of the compensator or other voltage controlling device 19, or directly to the line-wires 22. 20 and 21'represent two switch contacts in the control circuit, one of which is normally open andthe other normally closed. -Although these contacts are indicated as simple manually operated switches, it will be understood that my" automatic starter may be .used with any well known type of automatic switch, such as fluid-pressure governor,

. float-switch, time-switch, etc.

- The operation of the starter is as follows: If the switch 20 is closed momentarily, a circuit is completed from a line-wire 22 through switch 20, through switch-conta t 10, and magnet 3, to a second line-wire. Magnet 3 consequently draws up its core 6 and when this core strikes'the collar 7 on. the rod 4 it closes switch 1, with a quick movement. At the same time'the button 5 on the top of rod4 engages the switch con- .tact 10, raising it and breaking the circuit of magnet 3. The core 6 consequently begins to fall. Switch 1 remains closed, however, since the connection between this switch and the core is such as to permit the return movement of the core without movingthe switch, and since the switch is of the ordinary knife-blade type, the friction of the contacts is sufiicient to hold it closed. Core 6 moves downward slowly, since its return movement is retarded by the dashpot construction that. has been heretofore explained. Bythe closing of switch 1 motor M has been connected to intermediate points on the winding of the compensator- 19, and has consequently started. By the time the motor is up to speed thev core 6 has again reached its lowest position, and in this position the contact 11 carried by the core now engages the contacts 12 carried by the rod 4, since these. contacts have been raised by the closing-of switch 1. A circuit is thereby closed from a line-wire 22 through contacts 12 and 11,.magnet 13 to a second line-wire. Magnet 13 consequently draws up switch 2 with a quick movement, owing to the lost-motion construction heretofore explained, at the same time opening "switch 1 by the engagement of the projece tion 14' therewith. Rod 4 is consequently drawn down again to the position shown in Fig. 2, and this movement has two results.

In the first place, button 5 at the upperend of the rod is drawn away from contact 10, but this produces no efi'ect,'since button 15 has been raised into engagement with contact 1.0 so as to hold it open. Also the contacts '12 are drawn away from contact 11, thereby breaking the circuit of magnet 13. The core of magnet 13 does not fall, how'- ever, since it is engaged by the latch 16?: the no-voltage release magnets 17 being iien gized so as to draw up its core/ 1 By Fthe closing of switch 2 and the opening ofswitch 1 motor M is connected directly to the line and thus receives the full-line voltage for running It will be seen that when running connections are thus established, both operating magnets are out out of circuit.

The no-voltage release magnet 17 alone is energized, and thus this may be made comparatively small, very little energy is wasted while the motor is running. The motor continues to run until the voltage releasemagnet 17 is deenergized either by a fail-' ure of the line-voltage or upon opening the switch 21 in circuit with the no-voltage re-' 1 lease magnet. By means of this switch the motor may be stopped'whenever it is desired to do so. When the no voltage release-magnet 17 is deenergized its core falls,

'forcing the latch 16 out of engagement with the notch in the spindle 23, allowing the core of magnet 13 to fall. Owing to the lost-motion between this core and switch 2 the'core strikes the switch a hammer-blow, driving it open with a quick movement,

thereby breaking the motor circuit and bringing the motor to rest. At the same time contact 10 is allowed to fall, so that all parts are restored to starting position.

What I claim as new and desire to secure by Letters Patent of the United States, is, 1. In combination with an electric motor, a switch adapted to'iestablish starting connections, an operating magnet therefor and means for deenergizing the same when the starting switch is closed, a switch for establishing running connections, an operating magnet 'theretor, and means controlled by the first magnet for energizing the second magnet at a predetermined interval after the first m net is deenergized. 1

2. In com inationwith an'electri'c motor, a switch adapted toestablish starting connections, an operating magnet therefor, a switch for establishing running connections, an operating magnet therefor, means controlled by the first magnet and independent of the current for .energizing the second opening the starting switch when said second magnet is energized.

3. In combination with an electric motor,

a switch adapted to establish starting connections, an operating magnet therefor, a switchfor establishing running connections, an operating magnet-therefor, means controlled by the first magnet'for energizing the second magnet at a predetermined interval after the first magnet is energized, and a mechanical interlock between said switches. 4. In combination with an electric motor, a switch adapted to establish starting connections, an operating magnet therefor, means for deie'nergizing the same when the starting switch is closed, a switch for establishing running connections, an operating magnet therefor, a control circuit including the first magnet, and means for automatically energizing the second magnet a predetermined time after the control circuit is closed.

5; In combination with an electric motor, a switchadapted to establish starting connections, an operating magnet therefor, a switch for establishing running connections, an operating magnet therefor, a control circuit including the first magnet, means independent of the current for automatically energizing the second magnet a predetermined time after the control circuit is closed, and means for opening. the starting switch when said second magnet is energized.

6. In combination with an electric motor, a switch adapted to establish starting connections, an operating magnet therefor, a switch for establishing running connections, an operating magnet therefor, a mechanical interlock between said switches, a control circuit including the first magnet, and means for automatically energizing the second magnet a predetermined time after the control circuit is closed.

' 7 In combination with an electric motor, a switch adapted to e'stablishstarting connections, an operating magnet therefor, a switch for establishing running connections, an o erating magnet therefor, a control circuit including'the first magnet, means independent of the current for automatically energizing the second magnet a predetermined time after the control circuit is closed, means for automatically denergizing the second magnet when the running switch is closed, and a no-voltagerelease magnet controlling said running switch.

8. In combination with an electric motor, a switch adapted to establish starting connections, an operating magnet therefor, a switch'for establishing running connect-ions, an operating magnet therefor, means independent of the current and controlled by the first magnet for energizing the second magnet at a predetermined interval after the first magnet is energized, means for automatically deenergizing the second magnet when 'the running switch is closed, and a no-voltage release magnet controlling said running switch.

9. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a control system comprising automatic operating means for said switches adapted to close the starting switch and then to close the running switch and open the starting switch after a predetermined interval, means for deenergizing said operating means when the running switch is closed, and a no-voltage release magnet controlling said running switch. I

10. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a mechanical interlock between said switches, a control system comprising automatic operating means for said switches adapted to 'close first the starting and then the running switch after a predetermined interval, means for de'elnergizing said operating means when the running switch is closed, and a no-voltage release magnet controlling said running switch.

11. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a mechanical interlock between said switches, and a control system comprising automatic operating means for said switches adapted to close first the starting switch and then the running switch after a predetermined interval.

12. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, an operating magnet for the starting switch, means for deenergizing said magnet when said starting switch is closed, means for retarding the return movement of the core of said magnet, and means controlled by the movement of said core for closin the running switch and opening the starting switch.

13. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a ma net having its core operatively connecte to the starting switch, the connections between said core and said switch bemg adapted to permit the return movement spectively starting and running connections, a magnet having its core operatively connected to the starting switch, the connections between said core and said switch be-- ing adapted to permit the return movement of said core without moving said switch, means for breaking the circuit of said mag-' net when the starting switch is closed, means for retarding the return movement of the core, and means controlled by the movement of the core for closing the running switch and opening the starting switch.

15. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a magnet having its core 0 eratively connected to the starting switc the connec--' tions between said core and said switch being adapted to permit the return movement for retarding the return movement of the core, means controlled by the movement of the core for closing the running switch, and a mechanical interlock between the starting and running switches. I

16. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a magnet having its core operatively connected to the starting switch, the connections between said core and said switch being adapted to permit the return movement of said core without moving said switch, means for deenergizing said magnet when the starting switch is closed, means for retarding the return movement of the core, a magnet controlled by the movement'of the core for closing the running switch, means for deenergizing said magnet when the running switch is closed, and a no-voltage release magnet controlling said running switch.- o

17. In combination with an electric Inotor, two switches adapted to establish 1B6- spectively starting and running connections, a magnet having its core operatively connected to the starting switch, the connections between said core and said switch being adapted to permit the return movement of said core without moving said switch, means. for deenergizing said magnet when the starting switch is closed, means for retarding the return movement of the core,

, a magnet controlled by the movement of the core for closing the running switch and opening the starting switch, means for deene-rgizing said magnet when the running a switch is closed, and a novoltage release magnet controlling the runnin sw1tch 18. In combination, a knife-b ade switch,

an operating magnet therefor, connections between said switch and the core of said; magnet adapted to 'close sald switch whom tablish respectively starting an said magnet is energized and to permit the return movement of said core without moving said switch, means for deenergizing said magnet when said switch is closed, means for retarding the return movement of said core, and means controlled by the movement of said core for opening said switch. 19. In combination, a knife-blade switch, an operatin magnet therefor, a lost-m0- tion connection between the magnet core and a knife-blade switch in the motor circuit, an operating magnet therefor, a lost-motion connection between the magnet core and said switch, means for deenergizin said magnet when said switch is closed, an a no-voltage release magnet adapted to restrain sald core.

21. In combination, two knife-blade switches, independent operating magnets for said switches, lost-motion connections between each switch and the core of its operating magnet, and an interlock between said switches.

22. In combination, two knife-blade switches, independent operating magnets for said swltches, lost-motion connections between each switch and the core of its operating magnet, an interlock between said switches, and means for deenergizing each nliagniet when the switch operated thereby is c ose 23.; In combination, two knife-blade I switches, means for deenergizing each ma net when the switch operated thereby 1s closed, and a no-voltage release magnet con trolling. the core of one of said operating magnets.

24. In combination with an electric motor, two knife-bladeswitchesada ted to es tablish respectively starting an running connections, independent operatin magnets for said switches, an interlock etween said switches, a control system adapted to energize the magnet for the starting switch and then the magnet for the runnin switch after a predetermined interval, an means for deenergizing. the magnet of the starting switch when said switch is closed.

25. Incombination with an electric motor, two knife-blade'switches ada ted to es running connections, independent operating magnets for said switches, an interlock between said switches, a control system adapted to'energize the magnet for the starting switch and then the magnet for the running switch after a predetermined interval, means for deenergizing each magnet when the switch operated thereby is closed, and a no-voltage release magnet' controlling the running switch.

26. In combination, a knife-blade switch,.-

an operating magnet therefor, a lost-motion connection between the magnet core and said switch, means for deenergizing said mag-' 1 switch, means for deenergizing said magnet I when said switch is closed, a latch adapted to engage said core, a magnet controllin said latch, and a switch in circuit with sai latch-controlling magnet.

28. In combination with an electric motor, a knife-blade switch in the motor circuit, an operating magnet therefor, a lost-motion I connection between the magnet core and said switch, means for deenergizing said magnet when said switch is closed, a novoltage release magnet adapted to restrain said core, and a switch in circuit with said no-voltage release magnet. I

29. In combination with an electric motor, a switch adapted to establish starting connections, an operatingmagnet therefor, a switch for establishing running connections, an operatin magnet therefor, means controlled by t e first magnet for energizing the second magnet-at a predetermined interval after the first magnet is energized, means for automatically deenergizing the second magnet when the running swltch is closed, a no-voltage release magnet control-' ling said running switclpand a switch in circuit with said no-voltage release magnet.

30. In combination with an electric motor, a switch adapted to establish starting connections, an operating-magnet therefor, a

switch for establishing running connections,

an operating magnet therefor, a control circuit comprising the first magnet, means for automatically energizing the second magnet a predetermined time after the control circuit is closed, means for automatically deenergizing the second magnet when the running switch is closed, a no-voltage release magnet controlling said running switch, and

a switch in circuit with said no-voltag'e release magnet, I

31. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a control system comprising automatic operating means for said switches adapted to close the starting switch and then to close the running switch and open the starting switch after a predetermined interval, means for deenergizing said operating means when the'running switch is closed, a no-voltage release magnet controlling said running switch, and a switch in circuit with said novoltage release magnet.

32. In combination with an electric motor, two switches adapted to establish respectively starting and running connections, a mechanical interlock between said switches, a control system comprising automatic operating means for said switches adapted to close first the starting switch and then the running switch after a predetermined interval, means for denergizing said operating means when the running switch is closed, a novoltage release magnet controlling said running switch, and a switch in circuit with said no-voltage release magnet.

33. In combination with an alternatingcurrent motor, a voltage controlling device, two switches adapted to connect sald motor in different relations to said device for starting and for running respectively, operating.

magnets for said switches, and means controlled by the operating magnet of the starting switch for energizing the operating magnet of the running switch at a predetermined interval after. the first, magnet is energized.

34:. In combination with an alternatingcurrent motor,-a voltage controlling device, two switches adapted to connectsaid motor in different relations to said device for starting and for running respectively, operating magnets for said switches, a control circuit comprising the operating magnet for the starting switch, and means for automatically energizingthe; operating magnet of the running switch a predetermined time after the control circuit is closed.

35. In combination with an alternatingcurrentmotor, a voltage controlling device, two switches adapted to connect said motor in different relations to said device for starting and for running, a control-system comprising automatic operating means for said switches adapted to close the starting switch and then to close the running switch and open the starting switch after a predetermined interval, and means for deenergizing said operating means when the running switch is closed.

36. In combination with an alternating current motor, a voltage controlling device, two switches adapted to connect said motor in different relations to said device for starting and for running, a control system comprising automatic operating means for said switches adapted to close the starting switch and then to close the running switch and open the starting switch after a predetermined interval, means for deenergizing said operating means when the running switch is closed, and a no-voltage release magnet controlling the running switch.

37. The combination of an electric motor,

a switch adapted toestablish starting connections, operating means therefor, a switch for establishing running connections, operating means therefor, and means controlled by the first operating means for energizing the second operating means at a predetermined interval after the first operating means is energized.

38. The combination of an electric motor, aswitchiadaptedto establish starting connections, operating means-therefor, a switch for establishing running connections, operating means therefor, means controlled by the first operating means for energizing the second operating means at a predetermined interval after the first operating means is energized, and means for opening the starting switch when the second operating means is energized.

39. The combination of an electric motor,

a 'switch adapted to establish starting connections, operating'means therefor, a switch for establishing running connections, operating means therefor, means controlled by the first operating means for energizing the second operating means at a predetermined interval after the first operating means is energized, and a mechanical interlock be-' tween said switches. a

.40. The combination of an electric motor, two. switches adapted to establish start-ing and running connections respectively, a control system comprising operating means for said switches, and means controlled by the operating means for the starting switch forenergizing the operating means for the running switch at'a predetermined interval after the operating means for the starting switch'is ener 'zed.

41. In comblnation, an induction-motor, a supply-circuit, a transformenfa plurality of automaticallyoperated switches for first connecting the motor to the supply-circuit through the transformer-and then connecting the motor directly to the'supply-circuit.

42. Incombination, an alternatmg-current electric motor, an alternating-currentsupply circuit, a transformer, a plurality of separately-actuated switches for first connecting the motor to the supply-circuit through the transformer and then connect- I ingthe motor directly to the supply-circuit.

43. In combination, jan'? alternating-cur rent motor, an, alternatinlg-current supply circuit, a transformer, a p rality of automatically-operated switches for first connecting the motor tothe supply-circuit through the transformer and then connecta master controlling device for said-mainmotor-controller, a source of currentsupply, an electric motor, a"trans;former,and connecthe motor directly to the supply-circuit.

j A- minmotor controller, compris' a plurality ofsepafately-actuated contacts,

tions whereby when the master-controller is in one position the contacts are actuated to connect the motor to the source of supply by means of the transformer and when in another-position the contacts are actuated to connect the motor directly to the source of pp y- 45. A motor, a source of current-supply, a master-controller, transformer-windings, and means controlled by the master-controller for connecting the motor and source of supply through the transformer-windings in one position of the master-controller and for connecting the motor and the source of supply directly in another position of the master-controller. 46. An electric motor, a source of currentsu ply, transformer-windings, an automaticontrolled by the master-controller,- these contacts being adapted to connect the motor and the source of supply through the transformer-windings in one position of the master-control'ler and to connect the motor and the source of supply directly in another position of the master-controller. 7

48. In combination, an electric motor, a

plurality of separately-actuated contacts for first connecting the motor to the supply-cir cuit through the autotransfomner and then connecting thejmotor directly to the supplycircuit. f

49. In combination with an alternating. current motor, a voltage controlling device,

two switches. adapted to connect said'motor supply-circuit, an autotransformer, and a in different relations 'to'said device for start-.

.ing and for running, and a control system for said switches comprising meansv autos matically oplerating to close the startin switch'and t en to close the running switc termined interval: v

' and open the starting switch after a prede 50. The combination with a -motor, of a I com nsator, a com ensator switch .for connecting the. motor ereto, a running switch for connecting'the motor directly tothefline,

and a time relay device adapted after a predetermined interval of time to cause said compensator switch to be actuated'to disconnect the motor from the compensator and.

cause said running switch to be actuated to connect the motor directly to the line.

51. The combination with a motor, of a. and means for preventing said switches compensator, a compensator switch for confrom being closed at the same time. 10 meeting said motor wit-h the compensator, a In witness whereof, I have hereunto set running switch for connecting the motor dimy hand this 29th day of November, 1905.

rectly to the line, a time relay device for CHARLES D. KNIGHT. causing said compensator switch to be Htnesses: opened after a predetermined period and for BENJAMIN 13. HULL,

causing said running switchto be closed, HELEN ORFORD.

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