US1789063A - Motor controller - Google Patents

Description

Jan. 13, 1931. r. E. BARNUM MOTOR CONTROLLER Filed April 11, 1927 2 Sheets-Sheet 1 INVENTOR.

ATTORNEY Jan. 13, 1931. Tqg. BARNUM 5 I 1,789,063

MOTOR CONTROLLER Filed April 11. 1927 2 ShOOtfl-SIIOOE mmvrm 3, 5 i v 1 i v AITTORNEY starting connections In suc Patented 1 Jan. 13, I931 FU T ATBS EN s r c energize the starting switch and energize the running switch.

The present inventionhas among its objects to improve'the construction and operation of'starters of the aforesaid character.

Another object is to provide a motor starter of the aforesaid character havin im proved automatic timing means associated therewith.

Various other objects advantages of the invention will hereinafter appear.

The accompanying drawings illustrate an embodiment of the be described, it being understood that'the embodiment illustrated is susceptible of modification without departing fr e spirit and scope of the appended claims.

In the drawings:

Figure 1 is a front elevational view of a preferred form of motor starter embodying the invention.

Figs. 2, 3, 4 and 5 are detail side elevational views of certain of the parts illustrated in Fig. 1. g

Fig." 6 is a diagrammatic view illustrati the circuit connections of the controller, an

Fig. 7 is an across-the-linedia ram of the" control circuits illustrated in ig. 6, the

auxiliary contacts being shown in the position they occupy during starting. I Referring to Fig. 1, the same illustrates a starter for alternating current motors .including electromagnetically operated contactors land 2 mounted upon an insulating I iroroa conrnoma Application fled si -1i l1,

tothe supply circuit for running:

determined interval.

invention which will now i cooperating stationary contacts.

1087.; lmailn. 188,7. y

panel i As hereinafter set forth contactor 1 provides for establishment of starting con nections for the motor through the medium of auto-transformer windings, while contactor 2 provides for connection of the motor directly to the supply circuit forjrunning. Contactor 1 is manually controlled, and as hereinafter set forth upon closure thereof an automatic timing device is brought into action which' causes de-energization of said start ng contactor and one! 'zation of the running contactor after the flpse] of a pre- Starting contactor 1 and running 7 motor 2 are each rovided with an operating magnet 'of the c arac'ter shown in Fig. 4 comprising an operating winding 4 provided with a pivoted armature '5 supported between bearin members 6. Inthe following description t e operating winding of starting contactor l 18 designated by-reference character 4 and the operating winding of runningcontactor 2 by reference character 4". The armature ,5 of contactor 1 is op-' eratively connected to aLrotatable shaft 7 and said shaft carries insulated contact fingers 8 to 12, inclusive, each of which has a cooperating stationar tact fingers are norma in open position but upon energization of t e associated shaft 7 is rotated on its axis to move sai contact fingers into engagement with their As hereinafter-set forth contact fingers 9, 10 and 11 control the line connections for the motor during starting and to prevent excessive he 1 ing between these fingers and their coo erat-' ing stationary contacts upon jnterru tion of starting connections each is provide with a magnetic blowout device 13. The armature 5 0 running contactor 2 is operatively connected to a rotatable shaft 17 upon which are mounted insulated'contact fingers 18, 19 and 20, each of which has a cooperating stationary contact. The running biased to open position and u on energization of its 0 crating magnet t e shaft 17 is rotated to effect closure of contactfingers 18,

19 and 20. Each of the contact fingers 18,

19 and 20 has a blowout device 21 associated contact. Said con-- magnet contactor 2 is a ing therewith, said devices being similar to the blowout devices 13.

The starting and running contactors are provided with mechanical interlocking means com rising levers and 26 fixed to shafts 7 an 17 respectively. As best shown in Fig. 2 lever 25 is arranged so that the free end thereof projects into the path of lever 26 to prevent closure of the running contactor 2 while starting contactor 1 is in' closed position. However, for purposes hereinafter set forth said interlocking means permits partial movement of the running contactor 2 towards closed position while the starting contactor 1 is in closed position.

The timing device hereinbefore mentioned, is best illustrated in Fig. 3 and includes a contact arm 30 having a dash pot 3]. associated therewith, the latter being provided with a cylinder 32 and a piston 33 and being designed to rovide retarded upward movement of said piston and substantially free downward movement thereof. The cylinder 32 is fixed to insulating panel 3 and the same is provided with upstanding rojections 34 carrying a. pin 35 upon whic the contact arm 30 is pivotally mounted. The piston 33 is operativel connected to the contact arm 30 by a ro 36 having a hook portion 37 on the upper end thereof for enga ing a pin 38 fixed to said contact arm. ontact arm 30 carries a bridging contact 39 on the free end thereof and the same is biased by a spring 40 to move said bridging contact into engagement with a pair of stationary contacts fixed to panel 3 one ofwhich is illustrated by reference character 41 in Fi 3. Spring 40 has one end connected to t 0 contact arm 30 while the opposite end thereof is adjustably secured to a projection 42 on the lever 25. Lever 25 is also provided with a pro'ection 43 having an adjustable stop 44 t ereon for en aging a projection 45 on contact arm 30. v e .sto 44 normally holds the contact arm 30 in the position shown in Fig. 3, but upon closure of starting contactor 1 said arm is moved by sprin 40 against the action of the dash pot 32 to bring the bridgcontact 39 into engagement with contacts 41'. Upon opening of starting contactor 1 the stop 44 engages the-pro ection 45 on contact arm 30 to move the latter to open position and the dash pot piston 33 quickly returns to normal position under the action of gravity.

As best shown in Fig. 4, the operating armatures for the startin and running contactors are each rovide with downwardly extendin tail pieces 46 and the tail piece associate with the former contactor carries pins 48 and 49 on opposite sides thereof while the tail piece associated with the latter contactor carries ins 50 and 51 on opposite sides thereof. The pin 49 cooperates with a pair of stationary contacts 52 of the construction shown in Fig. 5, while the pin 50 cooperates with a pair of similar stationary contacts 53. As shown in Fig. 5 each of the stationary contacts 52 and 53 is yieldingly mounted upon a supporting bracket 54 which is fixed to insulatin panel 3 and the contacts 52 are arran e to be bridged by pin 49 upon closure 0 startin contactor 1 while contacts 53 are arrange to be bridged by the pin 50 upon closure of the running contactor 2. Pin 48 has a contact element 55 associated therewith which cooperates with a stationary contact 56 while pin 51 has contact elements 57 and 58 associated therewith which cooperate with stationary contacts 59 and 60, respectively. The contact elements 55, 57 and 58 are of similar construction and as best shown in Fig. 4 each of the same is provided with openings for receiving a pair of supporting ins 61 and 62 which are fixed to panel 3. lilach of the supporting cotter pin 63 a( jacent its outer end which forms a pivot for its associated contact element, while each of the supporting pins62 carries a spring 64 for biasing its associated contact element in a direction away from panel 3. The stationary contacts associated with contact elements 55 and 57 are of similar construction and as shown in Fi ."4 each of the same is fixed to anel 3 an is provided with a downwar ly projectin portion to be engaged by its associate contact element upon outward movement thereof under the action of the spring 64. For purposes hereinafter set forth contact elements 55 and 57 are normally held in open position by pins 48 and 51, and the arran ement is suc that the former contact e ement engages its contact 56 upon initial closing movement of starting contactor 1,v while the latter element engages its contact" 59 upon initial closing movement of running contactor 2. The stationar contact as shown in Fig. 4 is shorter t an the stationary contact 59 and the arrangement'is such that the same is engagedby contact element 58 when running contactor 2 is in open position. However, upon initial closing movement of the running contactor 2 the pin 51 permits contact member 58 to move outwardly under the action of its spring 63 for disengagement thereof with contact 60.

The operation of the aforedescribed autotransformerstarter and also the circuit connections therefor will now be more fully described in connection with Fig. 6 and Fig. 7. As shown in Fi 6 the starter provides for selective establis ment of starting and running connections for an alternating current motor M from a 3 hase supply circuit indicated by lines L, E and L. Lines 1 L and L are permanently connected to the stationary contacts associated with contact finpins 61 carries a scribed it is apparent that upon closure of gers 9, 10 and 11 and also to thestationary contacts associated with contact 'fingers'18, 19 and 20. The stationary contacts of contact fingers 8 and 12 arepermanentlycon nected to low voltage taps on auto-transformer windings C, C respectively, and compensator winding 0 is permanently connecte d' between contact fingers 9 and 10 While the compensator winding C is permanently connected between contact fingers 10 andll. Terminal T of the motor M is connected to contact fingers 8 and 18; terminal' T is permanently connected to contact fingers 10 and 19, while terminal T is permanently connected to contact fingers 12 and 20. With the connections above destarting contactor 1 the motor is supplied with low voltage starting current from lines L L L through the medium of autotransformer windings C and L while closure of running contactor 2 connects the motor directly to said lines for running.

Starting contactor 1 is controlled by a L normally 0 en start'push button and a normally c osed stop push button 66 and in g from line 1 operating windin said starting contactor is then established a conductor 74 through i for the operating winding 4 0 extendin from line L throu h push button 66, by conductors 72 and 73, to and through the normall closed contact element 58 associated with t e running switch 2, by the contacts 52 and thence through the operating winding 4 of the starting contactor to line L. 7

Upon closure of starting contactor 1 the timing device is brou ht into operation and after a given interval the bridging contact 39 thereof engages the cooperating stationary contacts 41. Upon engagement of contacts 41 by contact 39 an ener izing circuit the running contactor 2 is established extending from line L through push button 66, by conduc-- tor 75, through contacts 41, by conductor 76 to and through the operating winding of the running contactor and thence by conductor 71 to line L. Energization of the operating winding '4" of the running contactor tends to effect closure thereof, but as before stated, when the starting contactor 1 is in closed position the lever 25 associated therewith cooperates with the lever 26 associated with the running contactor 2 to ermit only parstarting contactor 1 2 1S maintained energized b g zing said starting switch and for e latter contacof the contact contact element ening ,ofconta'ct element 58 interrupts t e aforedescribed maintaining circuit. for the operatin winding of starting contactor 1 and sai ,contactor and the timing device associated therewith then return to normal position. During return of the contactor 2 efiects openi element ,58and closure 0 operating winding 4*fof running contactor a circuit extending from line L throug the normally closed push button 66, by conductors 72 and 78, through the contact element 55, by con-- ductor 79, through contact elementv57, b conductor 76, through theoperatin win ing 4', thence by conductor .71 to line L. This maintaining circuit is interrupted by opening of contact element 55 u on return 0 the starting contactor 1 to 0 position, but in the meantime the running contactor 2s has moved into closed. position and is maintained by a circuitextending from line through the contacts 53, by conductor 76, through the operating winding 4 ,of the running contactor 2'to line L. This maintaining circuit may be interrupted by depression of push button 66 to provide for return of the running contactor 2 to off position. Upon opening of the running 'contactor 2 there is atendency for the same to rebound. However, it should vbe noted that since the contacts 53 are bridged only upon full movement ofthe running, contactor 2 into closed position it is impossible for said contactor to rebound 'suflicientl to reestablish the aforedescribed maintaining circuit therefor.

- What I claim as newka'nddesire to secure by LettersPatent is: n

1. A controller for electric motors comprising two electrom gnetically operated switches, one-for starting and one fortunning, control means for said running switch including a time element switch memberto be set ino eration upon, response of said starting switch, and means operating upon response of said'running switch for eener-.

main.-

switche enrgi zed in-- time element switch tainin said runnin depen ently of sai; member.

2. A controller for electric motors comprising two normally open electromagnetically operated switches, one for startin and one for running, control means for sai running switch includin a spring actuated time element switch memier to be "set in operation upon response of said starting'switch, means associated with said running switch and acting 1 upon initial closing movement thereof to deener 'ze said starting switch,

1 through push button 66, by conductor 72,

to normalposition, the

and means associated with said running switch for maintaining the same energized indepindently of said time element switch mem r.

3. A controller for electric motors, comprising two electromagnetically operated switches, one for startin and one for running,mechanical interloc ing means between tarded in its action and set in operation by closure of said startingswitch, and means associated with said running switch and acting during said limited closing movement thereof to deenergize. said starting switch. 4. A controller for electric motors, comprising two electromagnetically operated switches, one for starting and one for running, a time element device arranged to act upon closure of said starting switch to establish an energizing circuit for said running switch and means acting upon a given closing movement of said running switch to deenergize said starting switch and to maintain said running switch energized independently of said time element device.

5. A controller for electric motors comprising two electromagnetically operated switches, one for starting and for running, a time element device arranged to act upon closure of said starting switch to establish an energizin circuit for said runnin switch, a mec anical interlock between said switches permitting a limited closing movement of said running switch upon closure of said starting switch and means adapted to act during said limited closing movement of said running switch to deenergize said starting switch and to maintain said running switch energized independently of said timing device during return of said starting switch to open position.

6. A controller for electric motors comprising two electromagnetically operated switches, one for starting and one for running, a mechanical interlock between said switches permitting a limited closing movement of said running switch upon closure of said starting switch, a time element device arranged to act upon closure of said starting switch to establish an energizing circuit for said running switch, means ada ted to act during closing movement of sai running switch to deenergize said startin switch and to maintain said running switch energized independently of said tifning device pending return of said startin switch to open position and means adapte to act only upon closure of said running switch to maintain the same energized inde ndently of said timing device.

. In a controller for electric motors, in

combination, two electromagnetically operated switches, one responsive to establish starting connections and the other responsive to establish running connections, a manually operated control switch for said startin switch. means for establishin a maintaming circuit for said starting switch upon closure thereof comprising normally closed contacts associated with said running switch and normally open contacts associated with said starting switch, a time element device arranged to act upon closure of said starting switch. to establish an energizing circuit for said running switch, and contacts associated with said running switch and acting upon closure thereof to shunt said time element device.

In witness whereof, I have hereunto subscribed my name.

THOMAS E. BARNUM.

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