US1060299A - Motor-controller. - Google Patents

Description

E. B. H. TOWER, JR.

MOTUR GONTRO'JLER.

APPLICATION FILED NOV. 26. 1909 Patented Apr. 29, 1913.

2 SHEETS-SHEET 1.

E. B. H. TOWER, JR. MOTOR CONTROLLER.

APPLICATION 1111,21) NOV. 26, 1909.

Patented Apr. 29, 1913.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

EDWIN B. H. TOWER, JR., OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER- HAMMER.MFG. 00., OF MILWAUKEE,

WISCONSIN, A CORPORATION OF WISCONSIN.

MOTOR-CONTROLLER.

Specification of Letters Patent.

Patented Apr. 2e, acts,

Application filed November as, 1909. Serial No. 529,909.

' To all whom it may concern .tact, tending Be it known that I, EDWIN B. H. Towns, J r., a citizen'of the United States, residing at Milwaukee, in the county of Milwaukee and State of \Visconsin, have invented new and useful Improvements in Motor-Controllers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to improvements in controllers for electric motors, and more particularly to controllers including a plurality of successively operating switches for accelerating the motor.

One of the objects of my invention is to provide means for temporarily checking the successive operation of the accelerating switches upon the occurrence ofabnormal conditionsin the motor circuit, or, in other words, to prevent the resistance from being removed from circuit too rapidly.

Another object of my invention is to provide each or any desired number of the ac celerating switches with an auxiliary 0011- to move therewith to cause energization of a succeeding switch and having a controlling winding for arresting its operation so long as abnormal conditions prevail in the motor circuit:

A further objectof my invention is to provide means whereby the auxiliary conportion of tact. of each switch, when operated, will remain in the same position, regardless of any subsequent surges of current through. its controlling winding.

Various other objects and advantages ofi my invention will be hereinafter clearly and fully set forth.

For the purpose of more clearly disclosing the nature and characteristic features of my invention, I shall describe the embodiment thereof illustrated in the accompany- It should, of course, be understood that my invention is notlimited to the particiilar embodiment thereof illustrated, but is capable of various modifications.

The views in the accompa'nying'drawing are as follows:

Figure 1 is a side elevation of a switch embodying certain features of m inventicn; Fig. 2 is an enlarged view of tlie upper Fig. 1, showing parts thereof in section; and Fig. 3 diagrammatically illustherethrough.

trates. a system of control employing switches similar to the one illustrated in Figs. 1 and 2.

The general structure of the switch illus trated' is of conventional form. Briefly described, this switch comprises a magnet frame 5 secured to a suitable insulating base 6 and having. pivoted thereto a contact arm 7. Mounted within the magnet frame 5 is a solenoid winding 8 having a plunger 9 connected by a pin 10 to the switch arm 7. The switch arm 7 has a main contact 11 and an arcing contact 12 arranged to engage relatively stationary contacts 13 and 14. The contact 13 comprises a laminated brush rigidly secured to a support 15 which is mounted upon the front of the magnet-frame and insulated therefrom. The contact 14 comprises av carbon block carried by an arm 16 which is-fulcrumed at 17, to the contact support- 15.' The solenoid'winding 8 has a stationary core 18 with which the plunger is adapted to seal when moved upwardly.-

Secured to the plunger 9 of the solenoid 8 is an upwardly extending tail rod 19, having loosely mounted thereon a contact disk 20. The contact disk 20 isadapted to bridge contacts 21 and 22 which are mounted upon posts 2-3 secured to and projecting forwardly from the insulating base 6. Surrounding the tail rod 19 is a coil 24 which is mounted within a magnet frame 25. The magnet frame may be of any preferred construction and supported in any suitable manner. As illustrated, the magnet frame is substan- "tially cylindrical and is provided with rearwardly extending lugs 26 secured to the insulating base 6 to form a support therefor. The top 27 of the magnet frame is preferably formed separate from the main portion thereof and provided with a cylindrical portion 28, projecting into the coil 24. Surrounding the portion 28 is a nonmagnetic bushing 29, preferably extending entirely through the coil 24;. The portion 28 forms a core for the coil-24, or, in other Words, the top-27, as a whole forms an armature for the coil. therein for permitting the tail rod 19 to pass The contact disk 20 is mountedon the upper end of the tail rod so to rest upon the top of the magnet frame, and said disk is preferably insulated from 1 both the tail rod and magnet frame. Upon the upper end of the tail rod is a nut 30 and The core 28 has a central aperture surrounding the tail rod between said nut and the contact disk is a coil spring 31. The spring 31 bears against the contact disk 20 and acts as a buffer to check the downward movement cf the plunger 9 of the solenoid 8.

' Fixed to the tail rod 19 below the core 28 is a collar 32. Surrounding the tail rod 19 and interposed between the collar 32 and the core 28 is acoil spring 33. With this arsuiiiciently energizedv to hold its core 28 against the pressure of the spring 33, said spring will compress or yield topermit continned operation of the contact arm 7. This compression of the spring 33 results in storing up energy, which will cause the core 28 to be raised as soon as the magnetic pull of the winding 24 decreases to a predetermined degree. As soon as the magnetic pull of the coil decreases to such an extent, the contact disk 20 will be moved into engagement with contacts 21 and 22. as the top of the magnet frame is raised, air gaps will be inserted in the magnetic path of the coil 24, thereby further decreasing the magnetic pull of said coil. It will, therefore, readily be seen that the coil spring 33 may be so designed. as to predominate the magnetic pulhof the coil 24 upon subsequent surges of current therethrough, thereby insuring the retention of the armature 27 and contact disk 20 in raised position until the solenoid 8 is deenergized.

I shall now describe the controller diagrammatically illustrated in Fig. 3. This controller includes switches 35, 36, 37 and 38 arranged to control an electric motor-'39, having an armature A and a series field winding F. Each of the switches 35, 36 and 3? is of substantially the same construction as the switch illustrated in Figs. 1 and 2, and the parts thereof will, therefore, be designated by the same reference numerals. The switch 38 is similar to the remaining switches, except that it is not provided with an auxiliary contact disk. The switches 36,

31'' and 38 are arranged tocontrol resistances It, i and R respectively connected 1n the motor circuit. Nhile I have shown series resistances, it should be understood that par allel resistances might be used if preferred.

1 shall now describe the operation of the controller, at the same time clearly setting forth. the circuit connections therefor, as-- suming that current is supplied from main J lines 40 and 41. For initially controlling It will be apparent that the operation of the several switches, I have shown a manually operated switch 42 adapted, when closed, to complete a circuit circuit which may be traced from main line 5 40, through said switch 35, by conductors 45 1 and 46, through the resistances R, R and R in series, by conductor 47 through the conj trolling coils 24 of the auxiliary contacts of switches 35, 36 and 37,-by conductors 48, 49 .and 50, through the Qunotor armature A and series field winding F to main line 41. The

motor is thus started with all of the resistance in circuit therewith. The coils 24 of the switches 35, 36 and 37 being connected in series with the motor, will, of course, vary in strength in accordance with the flow of current to the'motor. Hence, these coils may be so designed as to hold their armatures against the pressure of the springs 33 only when there is an abnormal flow of current in the motor circuit. Furthermore, these coils may be adjusted to hold and release their armatures at different current values. Hence, if an abnormal flow of current occurs in the motor circuit upon closure of switch 35, the coil 24 thereof will hold its armature 27 and auxiliary contact 20 against the pressure of the spring 33 until the flow of current decreases to the predetermined value. Thereupon the spring 33 will over come the magnetism of the coil 24 and raise the armature 27, thereby causing the auxiliary contact 20 to engage the stationary contacts 21 and 22. Of course, if there is no abnormal surge of current upon closure of the switch 35, the auxiliary contact 20 thereof will be immediately moved into engagement with the stationary contacts. Upon operation of the auxiliary switch 20, circuit will be closed from conductor 45 by conductors 51 and 52, through said auxiliary switch, by conductor 53, through the operating winding of switch 36, by conductor 54 to main line 41. Thereupon the switch 36 will respond.and shortcircuit the resistance B. from the motor circuit. Again, if an excesssive surge of current occurs upon shortcin cuiting the resistance R, the coil 24 of switch 36 will prevent operation of the auxiliary switch 20 thereof until the flow of current is reduced to the desired value. Thereupon the auxiliary switch 20 of switch 36 will operate and close a circuit from conductor 52 to conductor 55, thence through the operating winding of switch 37, by conductor 56 to conductor Thereupon the switch 37 will respond and shortcircuit resistance R.

Again, if an abnormal surge of current occurs upon shortclrcmtmg the resistance I R,'th'e auxiliary switch 20 of switch 37 will contacts, thereby completinga circuit from conductor 52, by conductor 57, to conductor 58, and thence through the operating winding of switch 38, by conductor 59 to conductor 56. The switch 38 will thereupon respond and shortcircuit resistance R Ihe motor circuit may then be traced from main line 40,,through switch 35, by conductors 45,

46 and 60, through switch 38, and thence through the motor as already traced. All resistance is thus removed from the motor circuit and the motor will be brought up to normal speed.

As previously set forth, the springs 33 of the several switches may be so designed as to prevent the attraction of any of the armatures 27 by the coils 24 after they have once been released. Consequently, each of theaccelerating switches, after having once responded, will be unaffected by any subsequent surges of'current in the motor circuit.

Having thus described my invention, what I desire to secure by Letters Patent, is

1. In a controller for electric motors, in combination, a plurality of automatic switches for accelerating the motor, means actuated by said switches for causing successive operation thereof, and electroresponshe means for arresting the operation of said first mentioned means while abnormal conditions prevail in the motor circuit, said first mentioned means being adapted to be arrested independently of the switches actusting the same.

2. In a controller for electric motors, in

combination, a plurality of automatic switches for accelerating the motor, a plurality of devices, each adapted to be actuated by one of said switches to cause the operation of another switch, and electroresponsive means for arresting the successive operation of said devices'while abnormal conditions prevail in the motor circuit, said devices being adapted to be arrested independentlyof the switches actuating the same.

3. In a controller for electric motors, in

switches for accelerating the motor, a plu rality of devices each adapted to be actuated by one of said switches to cause the operation of another switch, a'resilient connection between each of said devices and its operating switch, and a plurality of controllin windings, one for each of said devices, eac of said controlling windings being adapted to check the operation of its corresponding device while abnormal conditions prevail in the motor circuit.

5. In a controller for electric motors, in combination, a plurality switches, a plurality of devices each tendin to operate upon closure of one of sai switchesto cause the operation of another of said switches, a plurality of controlling windings, one for each of said devices, each of said windings being adapted to arrest operation of its corresponding device while abnormal conditions prevail in t-he'motor cir-- cuit, and means for retaining each of said devices in the position to which it is moved regardless of subsequent surges of current through its controlling winding.

6. In a controller for electric motors, a plurality of electroresponsive accelerating switches, a plurality of relay switches each operatively connected to one ofsaid accelerating switches and tending to operate therewith to energize another of said accelerating switches, and electroresponsive means for arresting the operation of said relay switches upon the occurrence of abnormal conditions in the motor circuit, the connection between each relay switch and its corresponding accelerating switch permitting .operation of the latter, while the former is arrested and positively operating the former upon restoration of normal conditions.

7. In a motor controller in combination, a plurality of electroresponsive accelerating switches, a plurality of relayswitches each operatively connected to one of said accelerat-ing switches and tending to operate therewith to energize another of said accelerating switches, and electroresponsive means for arresting the operation of said relay switches upon the occurrence of abnormal conditions in the motor circuit independently of their corresponding accelerating switches, the connection between eachrelay switch and its'corresponding accelerating switch insuring operation of the former upon restoration of normal conditions, and.

further insuring the retention thereof in the position to which it is moved regardless of subsequent surges of current 'in the motor circuit.

8. Ina controller for electric motors in combination, a plurality of electrores on-' pendently of the former, and a plurality of controlling windings one for each of said relay switches, each of said windings being adapted to arrest the operation of its corresponding relay switch upon the occurrence of abnormal conditions in the motor circuit.

9. In a controller for electric motors in combination, a plurality of electroresponsive accelerating switches, a plurality of relay switches, an operative connection between each of said relay switches and one of said accelerating switches, tending to cause the former to move with the latter but permitting the latter to move independently of theiformer, and a plurality of controlling windings one for each of said relay switches, each of said windings being adapted to arrest the operation of its corresponding relay switch upon the occurrence of abnormal conditions in the motor circuit, the connection between each relay switch and its corresponding accelerating switch insuring operation of the former upon restoration of normal conditions in the motor circuit and further insuring the retention o't its relay switch in the position to whichit is moved regardless of ,subsequent occurrences of abnormal conditions of the motor circuit.

1.0. In a controller for electric motors, in combination, a plurality of electroresponsive accelerating switches, a plurality of relay switches, each having a resilient connection with oneof said accelerating switches and tending to operate therewith to cause another accelerating switch to respond, and a controlling winding for each of said relay switches adapted to arrest the operation thereof upon the occurrence of abnormal conditions in the motor circuit.

11. In a controller for electric motors, in

combination a plurality of electroresponsive accelerating switches each being provided with an auxiliary contact adapted to causethe energization of another accelerating switch, a controlling winding for each of said auxiliary contacts adapted to prevent operation thereof while abnormal conditions prevail in the motor circuit, and resilient connections between each accelerating switch and its auxiliary contact adapted to have energy stored therein for operating its auxiliary contact immediately upon restoration of normalconditio-nsin the motor circuit.

152. In a controller for electric motors, in combination, a plurality of electroresponsive accelerating switches, each being provided with an auxiliarycontact adapted to cause the energization of another accelerating switch, a controlling windii'ig for each of said auxiliary contacts adapted. to prevent operation thereof while abnormal conditions prevailin the motor circuit, and resilient connections between each accelerating switch and its auxiliary contact adapted to have energy stored therein for operating its auxiliary contact immediately upon restoration of normal conditions in the motor circuit, and for' insuring the retention of its auxiliary switch in the position to which it is moved, regardless of subsequent surges of current through its controlling "winding.

13. The combination with an electric switch, of a device associated with said switch, an operative connection between said device and said switch tending to positively actuate said device upon operation of said. switch and electroresponsive means for temporarily checking the operation. of said deviceindependently of said switch.

14. The combination with.- an electric switch, of an auxiliary switch, an operative connection between said switches tending to positively operate the latter upon opera tion of the former, and an electroresponsive winding for holding said auxiliary switch against movementupon operation of said first mentioned switch.

15. The combination with anelectricswitch of an auxiliary switch, a resilient connection between said switches capable of having energy stored therein, and an electroresponsive winding for arresting the operation of said auxiliary switch upon operation of said first mentioned switch.

16. The combination with an electric switch, of an auxiliary switch, a resilient connection between said switches capable of having energy stored therein, an electro responsive winding for arresting the operation of said auxiliary switch upon operation of said first mentioned switch, said connec-- tion adapted to insure the retention of said auxiliary switch in the position to which it is moved, regardless of subsequent energization of said winding.

17. The combination with an electroresponsive switch, of an auxiliary contact therefor resiliently connected therewith, and an electromagnet {or holding said auxiliary switch stationary upon operation of said. first mentioned switch, said resilient connection being adapted'to have energy stored therein'to prevent attraction of said auxiliary switch by said magnet after the same has been released.

18. In combination wit-h a power circuit, a plurality of contactors intended for operation in succession to effect certain connections in said power circuit, auxiiiary switches cooperating with certain of said contactors, each arranged to control the operation of a succeedingcontactor, means for positively holding each auxiliary sw'i .ch open while its cooperating contactor is open, said means permitting each contactor to close independently of its auxiliary switch, but tending to positively move each aux tions in :said power circuit, 'auxiliar-y' switchescooperating with certain of said contactors, each arranged to control the operation of a succeeding cont actor, a mechanical connection between each contactor and its auxiliary switch for'positively holding the latter open when the former is open, 1:s v

and an electroresponsive controlling winding for each auxiliary switch adapted to holdthe same in open position under predetermined conditions, said connections being arranged to permit closure of each contactor while its auxiliary switch is held in open position and to positively move the latter to closed posit-ion when released by its controlling winding. i

20. In a motor controller in combination,

a plurality of electroresponsive acceleratingswitches, auxiliary switches associated With certain of said accelerating switches, each arranged to control the circuit of a succeeding switch, a mechanical connection between eachof said switches and its auxiliary switch tending to positively. close the latter uponclosure of the former, and an each auxiliary switchfor' preventing closure thereof while abnormal conditions prevail in the motor circuit, said connections being adapted topermit closure of each accelerating switch independently of its auxiliary switch when the latter is held open by its controlling winding.

In witness whereof, I have hereunto subscribed my name in the presence of two Witnesses. a

EDWIN B. H. TOWER, JR. Witnesses FRANK H. HUBBARD, S. W. Frrz GERALD.

electroresponsive winding associated with

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