US991206A - Controller for electric motors. - Google Patents

Description

A. J. HORTON CONTROLLER FOB. ELECTRIC MOTORS.

APPLICATION FILED JULY 6, 1908.

991,206. L I Patentd May 2, 1911.

' tion.

a slow speed time, and then automatically brought up to any predetermined maximum speed by the UNITED srn'rns PATENT" orricn.

ALBERT J. HOB-TON, F WHTTE PLAINS, NEW YCRK, ASSIGNOB T0,.1HE CUTLER- HAMMER MFG. 00., OLE MILWAUKEE, WISCONSIN, A CQRPORATION OF WIS- CONSIN.

CONTROLLER FOR ELECTRIC MOTORS.

Specification of Letters Patent.

Patented May 2, 1911.

Application filed July 6, 1908. Serial No. 442,174.

To all whomii may concern:

Be it known that I, ALBERT J. Ho'nron, a citizen of the United States, residing at White Plains, in the county ofWestchester and State of New York, have invented new and useful Improvements in Controllers for Electric Motors, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specifica- My invention relates to controllers for electric motors, and more, particularly to those for causing the motor to operate at different speeds.

One' object of my invention is to provide means whereby the motor may be operated for any desired period of manipulation of a single switch.

Other objects of my invention will be hereinafter set forth. 4

In the accompanying drawing I have diagrammatically illustrated one form of con-' troller embodying my invention.

The controller shown in the drawing comprises an electromagnetically operated main switch, an electromagnctically operated speed controller and a pilot switch for controlling the operationof said main switch and said controller. As will hereinafter he explained, the pilot switch also controls the direction of the flow of current through the motor.

The main switch 1 is carried by the plum ger 2 of a solenoid 3. This switch is provided with main contact brushes 4 and 5 and arcing contacts 6 and 7, which are carried on spring arms. The brushes 4 and 5 are adapted to engage stationary contacts 8 and contacts 10 and 1.1 are connected to the contacts 8 and 9.

The speed controller, which I have shown, is of the same construction as that shown in my former application, Serial No. 430,829, filed May 4, 1908.

speed controller comprises an arm 14 piv oted at 15. At its outer end, the arm 14 car- As thearm 14 is ries brushes l6 and 17.

' to one Generally described, the

moved the brush 16 is adapted to sweep over a contact segment 18 and a series of contacts 19, while the brush 17 is adapted to sweep over a series of contacts 21 and a segment 22. The contacts 19 are connected to a field regulating resistance 20, which is also connected end of the segment 18. All but the first of the series of contacts 21 are connected to an armature resistance 23, which is also connected to one end of the segment 22. The arm 14 is connected by an insulating link 24 to the plunger 25 of a solenoid 26. The solenoid 26 is provided with an adjustable core or plug 27 which is supported by a pivoted lever 28. The lever 28 is provided at. its free end with a handle 29 and a pin 30. The pin 30 is adapted to fit into any of the apertures 31 in a rack 32. This arrangement provides means whereby the lever 28 may be moved to, and maintained, in any desired position to adjust the position of the plug 27 within the winding 26. The lever 28 is provided with a lug 33 to which is pivoted a switch 34. The free end of the switch '34 is adapted to engagea stationary contact 35. A pin 37, extending through the plug 27 and projecting below the end there of, provides means whereby the switch 34 will be opened by the plunger 25 when the same reaches the limit of its upward movement. By usting the position of the plug 27 within the winding 26, the range of movement of the plunger 25 may be limited to any desired extent, which results in the limitation of the range of movement of the controlling arm 14. Hence, the controller may be set to cause any predetermined amount of armature resistance 23 and to insert any predetermined amount of field regulating resistance 20. The movement of the arm 14-is retarded by a dash-pot 38 which has its piston 39 connected to said arm. When the arm 14 is in its lowermost position. the brush 17. carried thereby, bridges the first trio of the contacts 21, while the brush 16 engages segment 18. i

.The pilot switch comprises a movable arm 40 pivoted at 41 and provided with an operating handle 42. The member 40 is of irregular shape and carries contact brushes 43, 44 and 45 which are arranged thereon in a staggered manner and radiallydisposed to the axis thereof. 'The brusliescarried by the i arm 40 are elongated and are each adapted the arm 14 tocut out to move over and engage with two sets of contact segments, which will now be described: The upper end of the brush 43 is adapted to engage either of the contact segments 46 or 47, while the lower end of said brush engages a contact segment 50. When the'arm 40 is moved to its extreme left-hand position, the brush 43 engages a contact 48, and when said arm is in its extreme righthand position, the brush 43 engages a con- .tact 49. At its upper end the brush 44 enga es the contact segment 50, while its lower ,en is adapted toengage either of the contacts 51 or 52. The upper end of-the brush 45 is adapted to engage either of the contact segments 52 or 53, While its lower end engages a contact segment 54. 'As shown in the drawing, the contact segments are so arranged that when the arm 40 is in a Vertical position the brush 43 lies between contact segments 46 and 47, and engages contact segment 50. The brush 44 also engages contact segment 50 and lies between contact segments 51 and 52, while the brush 45 engages contact segment 54 and lies between contact segments 52 and 53. The segments 46 and 47 are electrically connected and segments 51 and 53 are also electrically connected.

I shall now describe the circuit arrangement of the controller: Current is supplied from main lines 55 and 56.

- 56 is connected by conductor 57 to the con ment 54 of the pilot switch.

trolling arm 14. The contact segment 22 is connected by conductor 58 to contact seg- Contact seg ment 18 is connected by conductor 59 to one terminal of the shunt field winding f of the switch is motor, the other terminal of said winding being connected by conductor 60 to the main line 55. Contact segment 53 of the pilot connected by conductor 61 to contact 8. Contact segment 52 is connected by conductors 62 and 63 to one terminal of the motor armature a, the other terminal of the armature being connected by conductor 64 to contact 9. Contact 13 is connected to conductor 64. Contact 12 is connected by conductor 65, through a resistance 66, to conductor 63. Contact segment 50 is connected by; conductor 67 to main line 55. Main line 56- is connected :by conductor 68 to one ter-' to acne terminal of the winding 3,; :while the other terminal of the windingfiis connected by conductor 74 to-the first. of the. series of contacts 21,. which is cqnnectedithrough a resistance 75 byaconducton 7 6;to;ma in line 56.

The main line" Circuit will thengbe I. shall now describe the operation of the controller: Assuming that the arm 40 of the ilot switch is in the position shown in the rawing, the main switch will be open and the arm 14 in its lowermost position. It now the arm 40 be moved to the right so as to bring the brush 43 into contact with the segment 47, the brush 44 into contact with segment 52, and the brush 45 into contact with the contact segment 53, circuit will be closed through the operating winding 3 of the main line switch. This circuit may be traced from main line 56 by conductor 57 through the arm 14 to tacts 21 by conductor 74, through the winding 3 by conductor 73 to contact segment 47, across brush 43 to segment 50, and thence by conductor 67 to the main line 55. This will energize the winding 3 and cause the same to close the main switch 1, thereby raising the contacts 6 and 7 from the contacts 12 and 13. As soon as the main switch is closed circuit will be closed through the motor armature a. The armature circuit "may be traced from main line 56, by conductor 57 through the arm 14, brush 17, to the second of the series of contacts 21, through all of the resistance conductor 58 to contact segment 54, across brush 45 to contact segment 53, by conductor 61 to contact 8, across main switch 1 to contact 9, thence by, conductor 64 through. the armature a, by conductors 63 and 62 to contactlsegment 52, across brush 44 to contact segment '50, and then by way of conductor 67 to the main line 55. I

The shunt field winding f being connected across the supply circuit, the same will be energized before the armature circuit is closed. The circuit for the shunt field Winding f extends from main line 56 by conductor 57, through the arm 14, brush 16 to contact segment 18, thence by conductor 59 through the shunt field winding f, and by conductor 60 to the main line -55. In this position of the pilot switch it will be seen that all of the armature resistance 23 is included in circuit with the armature a, and, therefore,

the motor will be operated at a slow speed. The pilot switch may be left in this position as long as desired. The mot'or circuit may be opened at any time by merely moving the arm 40 back to a central position, which opens the circuit of thebperating Winding of the mainswitch. The main switch will then fall and open the motor circuit. When it is desired to increase the motor speed, the arm 40 of the pilot switch is moved to its extreme right-hand position, in which positionthe brushc43 willen age contact 49.

closed t ating; magnet 26 of the speed controller. This circuit extends from the main line- 56 by, conductor 68, through conductor. 69, through the arm winding 28, lug v33,

the first of the conirough the oper switch 34, contact 35 by conductor 71 to contact 48, by conductor 7 2 to contact 49, by

brush 43 to contact segment 50, and thence by conductor 67 to main line 55. The magnet. 26 will then respond and raise its plunger 25, thus raising the arm 14.

As shown in the drawing, the stationary plug is adjusted to permit the plunger 25 to raise the arm'14 until the brush 17 engages the contact segment 22, and the brush 16 engages the first of the contacts 19. It will merely inserting a portion of the field resistance, it should be understood that the device ma be set so as to insert all of the field resistance, or to remove only'a part of the armature resistance, as desired, according tothe speed at which it is desired to operate the motor. It will thus be seen that in the final position of the ilot switch the motor will be gradually brought up to the maximum speed and will continue to operate at a maximum speed until the main switch 1 is opened, or, until the brush 43 is moved oil? of the contact 49, whereupon, the winding 26 would be de'elnergized. and the arm 14 would fall; first removing the field resistance from circuit and then inserting the armature resistance in circuit. The motor would then continue to operate at a slow speed until the arm 40 of the pilot switch was moved to the position shown in the drawing.

, Upon the opening of the main switch 1, the contacts 6 and 7 carried thereby, will engage the contacts 12 and 13 and establish a dynamic braking circuit across the terminals of the armature a. This circuit may be traced from one terminal of the armature a. by conductor 64 to contact 13, to contact 7, across the spring arms of the main. switch to contact 6, to contact 12, thence'by conductor 65 through the resistance 66 and by conductor 63 to the opposite terminal of the armature. The establishment of the braking circuit just described, will quickly bring the Emotor to a state of rest.

\ As soon as the arm ,14 leaves the first of the series of contacts21 upon its upward movement, the short-circuit around the resistance 75, through said arm, is opened and said resistance insertedin circuit with the winding The circuit of the winding 3 will then extend from conductor 57 byconductor 76, through the resistance 75 to the first of the contacts 2, and thence through the winding 3, as already traced. The in- "SQI'tlOII of the resistance 75 cuts downthe fiow of current through the winding 3 to an amount just suflicient to maintain the main SWltCll closed, and prevents the winding from closing the main switch after the same has been opened It will thus be seen that after the main switch 1 is opened, either by the failure of voltage, or by the operation of the pilot switch, said main switch cannot again be closed until the arm 14reaches' its lowermost position, whereupon it will shortcircuit the resistance 75- and permit the winding 3 to respond. The motor is thus protected against damage in case an attempt is made to again start the same before the armature resistai ce is inserted in circuit.

If it is desired to operate the motor in the opposite direction from that previously described, the arm 40 of the pilot switch is moved to the left so as to move the brush 43 into engagement with the contact segment 46; the brush ,44 in cont-act with the segment 51, and the brush 45 in contact with segment 52. In this position of the pilot switch, circuit will first be closed through the winding 3 and the main switch 1 will be closed thereby, thus closing the armature circuit. The armature circuit may now'be traced from conductor 56, through the arm 14, through the resistance 23, contact ment 22, conductor 58 to segment 54, across brush 45 to segment 52, thence by conductors 62 and 63, through the motor armature a, by

. conductor 64 to contact 9, across switch 1 to contact 8, by conductor 61 to segment 53 of the pilot switch, across to segment 51, by brush 44 to segment 50, and thence by conductor 67 to main line 55. It will thus be seen that current flows through the motor armature in an opposite direction to that previously described, and, therefore, the m0- tor will run in. an opposite direction. The field circuitmay be traced as already described. When it is desired to cause the m0- tor to operate at its maximum speed, the arm 40 is moved to its extreme left-hand position, whereupon the brush 43 willengage contact 48 and close the circuit of the winding 26. The winding 26 will then respond and draw the arm 14 upwardly to: gradually remove the armature resistance from circuit and then insert the field resistance.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a controller for electric motors, in combination, an automatically operated main switch, a pilot switch adapted, when in a predetermined position, to cause said main switch to respond fdr obtaining a slow speed of the motor, and an automatically operated accelerating device arranged. to respond when thejpilot switch is moved to another position toincrease the speed of the motor, said pilot switch having contacts .included in the motor circuit for controlling the direction of flow of current therein.

2. In a controller for electric motors,

an electroresponsive mam combination,

switch, an electroresponsive accelerating device, and a pilot switch directly controlling the energizing circuits of said main switch and said accelerating device and movable into a position for causing response of the main switch alone for slow speed and into another position for also causmg the accelerating device to respond to increase the motorspeed, said pilot switch inherently controlling the direction of operation of the motor.

3. In a controlling device for electric motors,- in combination, an automatically operated main switch, an automatically operated speed controlling device, means for adjusting said device to cause the motor to operate at different predetermined speeds, and a pilot switch adapted, when in one position, to cause said main switch to be closed and when in another position to cause the operation of said speed controlling device.

4. In a controlling device for electric motors, in combination, a main switch, an electromagnetic winding for operating the same, a speed controlling device, an electromagnetic winding for operating the same, means for adjusting said controller to cause the motor to operate at dilferent predetermined speeds, and a pilot switch adapted, when in one position, to close the circuit of the operating winding of said main switch and when in another position to close the circuit of the operating winding of said speed controlling device.

5. In a controller for electric motors, in combination, a pilot switch having contacts for reversing the motor, an automatically operated main switch controlled directly by said pilot switch and adapted, when closed, to cause the motor to operate at a slow speed, an automatically operated accelerating device for the motor controlled by said pilot switch, said pilot switch being movable to cause the operation of both the main switch and accelerating device or the, main switch alone and means whereby the maximum speed oi the motor may be varied at Will-independently of said pilot switch."

6. In a controller for electric motors, in combination, 'a pilot switch movable in opposite directions for inherently varying the circuit connections of the motor to cause the same to operate in either direction, an electroresponsive main switch, and an electroresponsive accelerating device for the motor,

said main switch and accelerating device being controlled directly by said pilot switch,

and said pilot switch being adapted, when moved ineither direction, to cause both said tbh" and said accelerating device to respond to bring the motor up to a predetermined high speed or to cause the main switch alone to respond for obtaining a slow speed of the motor.

7. In a controller for electric motors, in combination, an automatically operated main switch, an automatically operated speed controlling device, means for adjusting said device to cause the motor to operateat different predetermined speeds, and a pilot switch adapted to cause the motor to operate in either direction, said pilot switch, when in certain positions, being adapted to cause said lnain switch to be closed and when in other positions to cause said speed controlling device to be actuated.

8. In a controlling device for electric motors, in combination, a main switch, an operating winding therefor, a speed controlling device, an operating winding therefor, means for adjusting said speed controlling device to cause the motor to operate at any predetermined speed,-and a pilot switch for causing the motor to operate in either direction, said switch, when moved in either direction, being adapted to first close the circuit of the operating winding of said main switch and then to close the circuit of the operating winding of said speed controlling device.

9. In a controller for electric motors, in combination, an automatically operated main switch, an adjustable automatically operated speed controlling device, a 'pilot switch adapted, when in one position, to cause said main switch to be closed and when in another position to cause said speed controlling device to be actuated, and a dynamic braking circuit across, the terminals of the motor armature adapted to be completed when said main switch is open.

10. In a controller for electric motors, in combination, an automatically operated main switch, an adjustable automatically operated speed controlling device, a pilot switch movable' in opposite directions to reverse the operation of the motor, said pilot switch, when moved in either direction, being adapted to first cause the operation of said said speed controlling device, and a dynamic braking circuit across the terminals of the motor armature adapted to be closed by said main switch when open.

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

ALBERT J. HORTON. Witnesses:

WILLIAM L. CULLY, CHARLES B. BAKER.

main switch and then cause the operation of

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