US1786554A - Motor-control system - Google Patents

Description

Dec. 30, 1930. H. L. VAN VALKENBURG MOTOR CONTROL SYSTEM F iled Oct. 19, 1926' 2 sheet -sheet;

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H L. VAN VALKENBURG MOTOR-CONTROL SYSTEM Fi led Oct. 19, 1926 Dec. 30, 1930.

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i Patented Dec. 30, 1930 UNITED STATES A ENT OFFICE I HERLION L, VAN VALKENBUBG, OF WAUWATOSA, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO SQUARE 1) COMPANY, OF DETROIT, MICHIGAN, A CORPORATION all geared together, the controller both caus-v {so as to brin the has et to convenient posi-.

ings, in which or MICHIGAN MOTOR- CONTROL SYSTEM Application filed October 19, 1926. Serial No. 142,626.

tates first in one direction for a certain period and then in the opposite direction for a 'period. One of the objects of the invention is to .provide a unitary system in which the motor, the machine and the controller are ing the reversal of the machine and reversing with it. This obviates the need of a separate motor for rotating the drum. Another object is to provide a type of apparatus. in which the controller may overrun without harm therebydoing away with the need of a Slip clutch or similar protective device. A

further object is to provide simple means by I which the machine ma be jogged or inched tion for loa ing and unloading. Still an other object is to 'provide simple and efficient apparatus in which the motor current is handled entirely b means of main switches So that the contro er does not have to carr a heavy .current. i I accomplish these objects by the mechanism illustrated in the accompanying draw- Figure 1 is a general view largely diagram- 'matic in its nature showing the general assembly, including the washmg machine, motor, main switch, drum controller in developed form, and the hand switches and push buttons.

Figures 2 to 6.are diagrammatic views showmg the drum controller in different positions. Like numerals denote like parts throughoutthe several views.

In the illustrated form the washing machine has a cylindrical basket 10 journaled in a frame12 and enclosed within a tub or container 14 inthe usual manner. The basket has a door 16 through which the machine may be loaded and unloaded. Power is supplied gears of the train there is fastened a shaft 22 provided with a pulley 24 connected by a belt 26 to another pulley 28 fastened to a shaft 30 provided with a worm 32 which meshes with a worm gear 34 fastened to the main shaft 36 of the drum controller.

In the drawings the controller is shown in developed form, that isin the flat.- The drum 38 is provided with a reversing segment R, a forward holding segment i and a backward holding segment g. In line with the segment R at one side are two fingers 40, 42 and at the other side are two fingers 44, 46. In line with the segment 7 are two contact fingers 48, 50, and'in line with the segment 9 are two contact fingers 52, 53. The contact fingers are stationary while the segments R, f, g rotate with the drum in the usual manner. 1

The drum controller just described constitutes the master switch. I will now describe the main switches through which the main energizing currents are carried to the motor:

In the form illustrated a three-phase system is employedhaving three main conductors A, B, C. These are connected to stationary contactso60, 62, 64 adapted to be engaged by switch arms 61, 63, 65 respectively.

These arms are controlled by a rod 66 which is longitudinally movable and is urged by a spring 68 to hold the switch arms in open position as shown in Fig. 1. For identification this will be termed the forward. main switch. The arm 61. is connected by a conductor 70 to a conductor 71 constituting one of the motor leads. Arm 63 is connected by a conductor 72 to a conductor .7 3 which constitutes another of the motor leads, and arm 65 is connected by a conductor 74 to a conductor 75 which constitutes the third motor lead. ;Foroperating the machine in the reverse direction there is what may be termed a backward or reverse main switch. This includes three switch arms 76, 77, 78 which are connected respectively to the conductors 75, 73, 71. The arms are adapted to engage contacts 80, 81, 82 respectively which are conne cted by conductors 83, 84, 85 to the contacts 60, 62, 64 respectively. Said arms are operated by a switch rod 86 which is urged by a spring 88 to hold the switch arms open.

Switcharm 66 is controlled by a winding F, one end of which is connected by a conductor 90 to the main supply conductor A. A movable core 91 is located within the field of winding F and is connected to rod 66 with the result that when the winding is energized, the switch arms 61', 63, will close. The other end of winding F is connected by a conductor 92 to a stationary contact 93 which is connected by a conductor 94'to the finger 40 on the drum. The circuit through the winding may be completed through the re versing segment R and finger 42 by'a conductor 96 whichis connected to a conductor 97 connected to the finger 48. Said finger is connected to the finger 50 by the holding segment f. A conductor 98 connects finger 50 with a conductor 99 which leads to the switch terminal 100 of the hand-operated change switch E. The other terminal 101 of this switch is connected by a conductor 102 to a conductor 103 which is connected to a hand-operated service switch D. The stationary contact 104 of this service switch is connected by a conductor 105 to the main line conductor C.

The switch rod 86 is controlled by a winding G which controls a movable core 110 fastened to the rod in such manner that when the winding is energized the switch arms 76, 77, 78 will close. A conductor 112 connects one end of winding G to the conductor 83. At the opposite end the circuit through the winding is completed by a conductor 113 which leads to a, contact 114 which is connected to a conductor 115 which leads to the finger 44. The reversing segment B may connect the finger 44 to the finger 46 which is connected by a conductor 116 to a conductor 118 which is connected to finger 53. This finger may be connected by holding segment 9 which is connected to conductor 99 which leads to the main supply conductor C in the manner previously described. The forward main switch rod 66 is connected to and operates a holding switch 120 which is connected to conductor 96 and is adapted to engage contact 93. The backward switch rod .86 is connected to and operates a holding switch 122 which is connected to conductor 118 and is adapted to engage contact 114. These holding switches 120, 122 are closed by the switch rods at the same time that the main supply switches close.

Now to describe the switches by which the motor may be started or by which it and the basket of the washing machine may be jogged or inched when necessary for loading or unloading: For inching, the drum controller is put out of service by opening the change switch E and then closing the circuit for one or more short periods through the motor to cause it to rotate the required amount. This is done by momentarily closing the forward or backward main switch, as the case may be. To rotate the motor backwards the operator closes the normally open push button 130 which is connected to the conductor 102 and .is adapted when closed to engage'the contact 142 which is connected by a conductor 144 to conductor 94. I r Y Operatz'0n.Let it be assumed that the motor is at rest in its mean position and the various switches open and the drum controller in approximately neutral position, all as shown'in Figure 1. If now the operator wishes to start up the motor and cause the machine to operate automatically, in distinction to inching, he closes service switch D and change switch E and presses one of the push buttons 130 or 140. It is immaterial in which direction the machine starts to rotate, and to conform to the selected diagrams let it be assumed that he wishes the machine first to rotate backward. He pushes button 130 to closed position whereupon the winding G is energized and closes the switch arms 76, 77,78, which energizes the motor and causes it to rotate in what may be termed a backward direction.

The winding is energized as follows: from supply conductor A to contact 60, to conductor 83, to conductor 112, to winding G, to conductor 113, contact 114, conductors 115 and 132, contact 131, push button 130, conductor 103, switch D, contact 104, conductor 105 and main supply conductor C. The movement of the switch rod 86 to closed position closes the holding switch 122 and thereafter the windingG is kept energized as follows: from supply conductor A to contact 60, conductors 83 and 112, to winding G, thence by conductor 113, contact 114, holding switch 122, conductor 118, finger 53, segment g, finger 52, conductor 99,- contact 100, switch E, c0nductors 102, 103, switch D, and conductor 105 to main conductor C. As the motor rotates it displaces the drum from the mean position shown in Figure 1 toward the left to the position shown in Figure 2 where the segment g has moved out of engagement with the fingers 52, 53, thus opening the circuit through the winding G and permitting sprin 88 to open the main switch and incidentafl open the holding switch 122.

The motor current is now cutoff but the motor will continue to drift and further displaces the drumcontrollcr'to the position shown in Fig. 3 in which the reversing segment R- engages the fingers 40, 42 which completes the circuit through the forward winding F in the following manner, it being understood that the holding segment f still remains in engagement with" the fingers 48,

50; from the supply conductor .A to conductor 90 to winding F, thence through conductor 92, contact 93, conductor 94, finger 40, segment R, finger 42, conductors 96 and 97,finger 48, segment f,finger 50, conductors 98, 99, switch E,- conductors 102 and 103, 7

switch D, and conductor 105 to the supply conductor C. As a result of energizing the winding F the forward switch arms 61, 63, 65 close and supply the motor, the phase relation being changedand the motor rotating in the opposite or forward directionv-The closing of the forward switch incidentally closes the holding switch 120, with the result that thereafter the winding F is kept energized through the following circuit: From conductor A to conductor 90 towinding F, thence to conductor 92, contact '93 holding switch arm 120,- conductors 96 and 97, finger 48,segment f, finger :50, conductor 98, conductor 99, switch E, conductors 102 and 103, switch D and conductor 105 to the 2a supply conductor 10. F

' As the motor is now reversedit will cause the washing machine and the drum controller to rotate inthe opposite direction and they controller to move; toward the right from the position :shown in Figure 3 to the position shown in Figure 4. This latter figure shows the drum after it has rotated the major portion of its normal travel. The segment fhas left the fingers 48, 50,-thus opening the 35 circuit through the windi F 'and incidentally opening'the holding switch 120. The spring 68 now'opens the forward switch arms 61, 63, 65, thus cutting oil the motor,

which however continues to drift-until the position shown in Figure 5 is reached, where the, reversing segment [It has reached the fingers 44, 46. The segment g, however, still remains in contact with the fingers '52, 53. Thereupon the motor will begin to work for the winding G willbe energized as fol-- I, lows: from the supply conductor A, contact, "60, conductors 83 and 112 to'the winding, G, thence through the conductor 113, contact 114, conductor115, finger 44, segment R, finger 46, conductors 116 and 118, finger 53, segment g, finger 52, conductor 99, switch E, conductors 102 and 103, switch D, and conductor 105 .to the main line. conductor C.

The closing=of the main switch closes the holding switch 122, which will keep the winding Genergi'zed-in the manner previously:

described. Thus itwill be seen that-the mo? tor is-caused to rotate alternately inoppositedirections for-a predetermined number of rotations and -the action will be entirely automatic after the push button; has been. pressed for starting the system.

IIt will be noted that-either ofthe push buttons 130 or 140 may be employed for starting up the apparatus after the switche's D and E have been closed. 'The closing of the I switch 140 will cause the ener 'zation of winding F-to start the motor in a orwarddilrection in the following mariner: from: the .supply conductor 'A to the" conductor .90 and coil F thence through the'conductor 92 .to the 142, switch 140, conductor 10?), switch D, and

Contact .93, conductors 94 and 144, contact conductor 105 to the 'supply' conductor C.

Afterthis coil F is onceenergized it closes the holding switch 120 which thereafter-keeps the" coil energized so long as-the'segment remains in contact with the fingers-48, 50.

greater or less distance, as the case may be, to bring-thedoor 1.6 to proper position] for inserting or removing the'clothing, or" other goods to be treated; -This supplemental ro-- I tar-y movement or*inching will beaccom- 'to'changing from automatic to hand control. Suppose that he wishes the machine then to Assume now that the washing operation is complete, and'that the washing machine is to be unloaded. Ordinarily it will be necessary torotatethe basket'gforward orbackward a open the change-switch E as a preliminary 'move forward a'short distance. He will I press the push button '140 which will energize the forwardcoil- F asfollows:

From the supply conductor A to the conductor 90, to coil F,thence throughconductor 92 to contact 93, conductor 94, conductor 144,

contact 142, switch140, conductor 103, switch D, conductor -105 through the main supply conductor 0. Energizing the winding will close the main switch arms 61, 63, 65. The

operator will hold the hand switch closed only'for a moment, which will jog the motor forward. Hthe movement is insuflicient the action can be repeated. If instead of de.-'

siring the machine to move forward the operatorwishes it to move backward, he will 3 press the push button 130 which will energize supply conductor A to contact 50, to eonduc and 132, contact 131, switch 130,"conductor 103, switch D and conductor to the main conductor C. This switch 130 will be held.

closedonly' momentarily forrone or more the backward coil G as follows: from the tors 83 and 112, to the coil, thence through conductor.113, contact 114,conductors times although after an operator becomes experienced he may be'able' to estimate the of the basket.

In the form shown, is designedto rotate about 180 degrees, first in one direction and thenin the other. 'Ilhere may be occasions, however, when the motor" will cause the drum controller to Qverrun: For example, if the operator cuts ofl the current by opening the switch E 'at a'momentj. when the parts arein a position-su'chas that illustrated in Figure 4 where the reversing.

amount of time the push buttonswitch must be heldclosed to cause the. desiredmovement he drum controller segment R is near the end of its travehbut drift for a considerable distance, for instance,

to a position such as that shown in Figure 6. But no harm will be done, for the motor may 'be jogged independently of the drum controller, that is, by using the push buttons 130 or 140 in the manner already described. If the operator wishes to recommence automatic operation all he will have to do will be to hold one of the push buttons closed long enough to cause one of the segments f or g to engage their cooperating fingers. Thus the drum controller is not required to have any definite stopping point and there is no need of a slip clutch or similar device for protecting the applaratus from wrecking itself.

aving thus described my invention, what I claim as new and desire to secure by Letters Patent isi 1. In a system for driving and periodically reversing a rotatable body, an electric motor .for driving said body, magnetic switches, one

for causing the motor to rotate forwardly and the other backwardly, a rotatable controller connected to said body to rotate therewith, the normal zone of operation of the controller being less than a complete revolution, and

' means controllable at will and independent of the controller for inching the motor to bring the controller back into the zone of operation in case it should over-travel.

2. A system for driving and periodically reversing arotating body having an electric motor connected to said body for driving it, a pair of magnetic switches, one for causing the-motor to rotate forward and the other backward, a drum controller for operating said switches, means for rotatingthe drum first in one direction and then in the opposite direction in synchronism with the rotating body, the drum having a normal zone of operation which is less than a complete revolution, and an inching switch arranged in parallel with the drum controller for holding .a main switch closed and thereby causing rotation of the motor independently of the drum whereby if the drum has rotated past itszone of operation the inching switch can be employed to bring it back.

3. In a reversible motor controlling sysrotatable drum controller mechanically connected to the motor for reversing rotation therewith, said controller having a pair of holding segments for maintaining each and operating circuit of a said switch, said seg ments being arranged circumferentially of the controller, the opposed ends of the se ments beingarranged in overlapping and in spaced relationship, and a reversing segment arranged in the circumference of said controller at a point opposite the space between the spaced ends of said holding segments.

' 4 In an electric power system for driving and periodically reversin a rotating body, a motor connected to said body for driving it in either direction, a main switch for operating the motor forwardly, a second switch for reversing the motor and a movable controller connected to the rotating body, and movable forwardly and backwardly in synchronism with it, a circuit for operating said main switch, and a second circuit for controlling said reversing switch, said controller having a pair of elongated holding segments with spaced apart ends and arrangeable, each in one of said operating circuits to close the same, and ashorter reversing segment rotating intermediate the ends of the holding segments for normally energizing one or the other of said operating circuits, the operation tem, a motor, a switch for causing the motor A

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