US1484046A - Starting switch - Google Patents

Description

Filed April 5, 1925 3 Sheets-Sheet Feb. 19, 1924. 1,484,046

c. H. WELLINGTON STARTNG SWTCH Filed April 5. 1925 5 Sheets-Sheet 2 'IIII Feb. 4'9, 1924. 1,484,046

lC. H. WELLINGTON STARTING SWITCH Filed April 5, 1925 3 SheeS-Sheet 5 JNVENTOR 'BY Char/@5 h/e/g/o/y ATTORNEYS Patented Feb. 19,1924. IIT'ED` STATES CHARLES H. WELLINGTON, QF VENTURA .PATENT oFFIcE.

, CALIFORNIA, ASSIGNOR TO CASEY- MANU- FACTURING COMPANY, OF OXNARD, CALIFORNIA, A PARTNERSHIP COMPOSED OF CHARLES H. WELLINGTON, OF VENTURA, CALIFORNIA, AND CHARLES L. HIRT, OF

OXNARD, CALIFORNIA.

STARTING SWITCH.

Application led April 5, 1923. Serial No. 629,990.

To all whom it may concern:

Be it known that I, CHARLES H. WELLING- TON, a citizen of the the United States, and resident of Ventura, in the county of Ventura and State of California, have invented new and useful Improvements in a Starting Switch, of which the following is a specification. f f

`This invention relates to a switch mechanism for electrically connecting a single phase induction motor having a split phase starting winding to a source of electrical energy. One method vof starting and bringing up to speed a single hase induction motor is to employ a starting .windin of the split phase type. This split phase winding is designed only for starting and when the motor reaches full speed, it should be disconnected from the line in order to pre- 20, serve the winding against injury and to kee the motor operating efficiently. f hev rimary object of this invention is to provide a switch mechanism and running windings so connected -that only a limited current is admitted to the windings at starting. More particularly, I employ a lurality of running windings in paralle connecting less than the total number of running windin to the line at starting, and connecting al the runningwindings to the line when operating at full speed. f

These objects together withfothe'r objects and corresponding accomplishments are ob'- 'tained by meansvof the .embodiment ofmy invention illustrated in the accompanying drawing, in which: 1

Fig. 1 is a 1an view of a com lete mechanism adapt/e for connection tween the 4line and the motor; Fig. 2 i's a section as seen on the line 2-2 of Fig. 1 showing the elements of the structure inl elevation; Fig. 3 is a section as seen on the line"'33 of Fig. 2; Fig. 4 is a section as seen on the line 4 4 of Fig. 1; Fig. 5 is a wiring dia.-

ram; and Fig. 6 is an end elevation of t e complete structure.

Referringl more particularly to Fig. 5, lthe rotor of an induction motor is indicated by A. B and C indicate the running windv ings and I) the split phase starting windking. For the purpose of indicating that thereis a difference in phase, acondenser. is conventionally shown in series with-the starting winding, although' in practice no b 7 ellectromagnet L. The other terminal of the electromagnet L is connected by a conductor M to a contact N2' of a switch, theswitch being indicated generally by N. The contact N2 is connected by a conductor O to the motor winding C. Contact N1L is connected to themotor windin B. Contact N? is connected to the line lea F. Contact N is connected to one terminal of an electromagnet P'. The other terminal of the electromagnet is connected by a conductor R to the motor windin D.l A manually operable contact finger is arranged to be laced in engagement with switch contacts 2, N3, and N4. Avcontact finger'T is arranged to engage contacts N1, N2, and N3. The contact finger T is operated by a differential armature U controlled by electromagnets .L and P. r f A Referringfto the wiring diagram, assume that'switch J is closed, this being its normal condition. The switch mechanismy is now operated to bring switch finger S .into engagement with contacts N2, N3, and N. At this time, switch fnger'T is out of engagement with the switch contacts.' Current -now'ilows from the line lead F to contac-t- Ns and through the switch vfin r S to'contacts N2 and. N. Current wil fiow from contact N'g'through the conductor O to the running winding C of the motor and ,through the conductor G to the line lead E. Current also 'flows from the 'contact N* through the electromaigrnet- P, conductor R, through the starting winding D, from` the starting winding `through the conductor .G to the line lead E. Current will also ilow from the conductor `N2 through *he conductor M, electromagnet L, conductor K switch J, and conductor'H to the line lead E. This lplaces the runningwindi and starting winding D on the line. A field is produced'in the stator to cause rotation ofthe rotor and the latter picks up speed finally. attaining full speed. The motor windings admit a relativel large current when the motor is initial y connected to the line. This current decreases as the s eed of the .rotor increases. The current t rough the motor starting winding D will be a minimum when the motor has reached its full speed. The energization of the electromagnet P is a minimum when the motor is at full speed due to being in series with the motor winding D. Assuming that the line voltage is constant, which is the normal condition of the line, the current passing through electromagnet L is constant, it being shunted across the line. This produces an energization of the electromagnet L which is constant, and a constant pull upon the armature U- by the electromagnet L.

The normal position of the armature is that shown in Fig. 5 with the armature resting against the pole of the electromagnet P. The armature is pivoted .at V between the electromagnets. Vhen the motor reaches full speed, the pull of electromagnet P upon the armature U will be overcome by the pull of' the electromagnet L upon the armature. rlhe armature is then caused to rock so that it rests against the pole of electromagnet L. This causes the contact finger T to be moved into engagement with' contact N1, N2, and N3. The effect of this is to connect the contact N1 with the line lead F. Current then fiows from the line lead F through contact N3, finger T, contact N1, by way of conductor Q to the running winding B and then through the conductor G to the line lead E.v With the contact fingers S and T in engagement with the contacts 1 1, N2, N 3, and N4, running windings B and C and starting winding D are all in circuit. Contact finger S mayv now be disengaged. This disconnects the contact N4 from electrical connection with the contact Ni43 through the finger S and thereby disconnects it from the line lead F. Electromagnet P is deenergized and the starting winding D is disconnected. The motor now operates with the running windings B and C. The motor will continue to operate until finger T is disengaged from contacts N1, N2, and N3. This might be accomplished by pulling finger T 'away from the contacts against the action of electromagnet L. Another method is to deenergize the electromagnet L, which may be accomplished by opening switch J. The normal position of the armature being that shown in Fig. 5, with the electromagnet deenergized. the armature will now rock to draw the fin'ger T away 'from the contacts. The operator can judge the time that this may occur either by experiments as to the time it requires for the motor to reach its full speed, the sound of the click of the contact finger T as it goes into engagement, or from watching the motor. At this time, the finger S should be disengaged from its contact. At the time that it is desired to stop the motor, switch J is opened. It will be noted that only one running winding is in circuit when the motor is started. As the running winding initially pulls a large current, the amount of current required for the motor will be decreased by dividing the running winding and using only a portion thereof at starting, then when the motor has attained full speed throwing in the other divisional portion of the winding.

The mechanical elements whereby the above described electrical functions are accomplished will now be described. Plates of insulatingmateriai are indicated 'by 7 and 8. The plates are connected at one end by posts 9 and 10. At the other endbars 11 and 12 connect the plates. This forms a frame to support the elements. In Fig. 6 the bar 12 is shown broken out to better disclose the structure.

Mounted upon plate 7 is a block 14 having binding posts 15 and 16 for connection to the service leads. The service leads are brought in and connected to these posts. Mounted upon a block 17 connected to the plate 7 are binding posts 18 and 19 which are connected to spring fingers 2O and 21, best shown in Figs. 1 and 4. A roller of electrical material indicated by 22 engages the fingers 20 and 21 thereby making contact. The fingers 2O and 21 and the roller 22 correspond to the switch J shown in Fig. 5. An electrical conductor connects the binding post 16 and the post 18. The post 19 is connected by a conductor to the winding 23 of electromagnet L. The roller 22 is journalled upon an arm 24 and is ininounted as indicated by 25, upon a bracket 26 which is secured to the core 27 of the electromagnet L. The core 27 is of bipole type. The core and the elements mounted thereon are secured to the plate 8 by posts 28. Pivotally connected to the end of arm 24 is a rod 29 having at the end thereof a push button 30. A tension spring 13 is connected to the rod 29 and tends to hold the latter in a position such that roller 22 is maintained in engagement with fingers 20 and 21. Thus, normally the switch J is maintained closed. Pressure upon the button 30 will swing the arm 24 so as to break the contact between the roller and the fingers. This opens the switch.

Mounted upon the bar 12 and insulated therefrom are contact fingers 31, 32, 33, and 34 corresponding to the contacts N1, N2, N3, and N4, shown in Fig. 5. These contacts are designated as a group by the letter N in the several figures. The' contacts are bent at right angles 'and depend from the bar 11. The ends adjacent the bar are sulated therefrom. The arm 24 ispivotally provi'ded with binding posts for connection to the various electricalconductors.

One terminal of a running winding of the motor is adapted to be connected to the bindinvr post on contact 31. Contact 32 is adapted to connected to the corresponding terminal ofthe other running winding and to aterminal of a coil 23 of electromagnet L. Contact `33 is connected to binding post 15, thereby connecting it tol a line lead. Contact 34 is connected by a conductor to the winding 35 of electromagnet P. A bracket 36 extends from the bar 12, and journalled between it and a footofthe bar l2 where it is connected to the plate 7 is a square shaft 37. Upstanding from the shaft 37 are lingers -38, 39, and 40. These three fingers 'are electrically connected and constitute in effect one finger corresponding to the finger S shown in Fig. 5. Three fingers instead of a single finger have been used for mechanical reasons. A crank arm 41 is secured to' the shaft 47 foi` rocking the latter. It has a button 42 pivotally connected thereto and a-spring 43 tending to' hold .it in'such a position that the fingers S are out of engagement with the contacts N.

In starting the motor the button 42 is pressed inwardly to bring the fingers S in engagement with the contacts N and is held in this positionv until the motor has reached full speed. Thereupon,pressure upon the button is released.

Journalled in the plates 7 and 8 is a square shaft 44 having upstanding therefrom fingers 45, 46, and 47 electrically connected to each other and in effect comprising onefinger correspondingl to the finger T shown in Fig. 5. These fingers are disposed to be rocked into engagement with the contacts N. Secured to the shaft 44 are spaced arms 48 and .49. By rocking the\ar ms the contact fingers T may be moved into and out of engagement with the contact N.A Pivotally mounted between the'arms 48 and 49 is an armature 50 arranged to span the whole piece of electromagnet L. Pivotally mounted betweenthe arms48 and 49 on the other side of shaft 44 is an'armaturc 51 arranged to be controlled by electromagnet P., Itwill be noted that the arms 48 and 49 with the electromagnet supporting them are soarra'nged that gravity willV cause the armature 51 to rest against the pole piece of electromagnetP.

In starting the motor` button-42 is pressed inwardly and held in this position. This connects one running winding and the starting winding through the series magnet P, and also;y the shunt electromagnet'L to the line. As soony as the motor has reached full speed, the electromagnet L overcomes the action of electromagnet P and rocks the shaft 44 bringing fingers T into engagement with contacts N. As soon as the motor has reached its full speed, as may be determined by the operator, button. 42 is released, whereupon spring43 causes the shaft 37 to be rocked and contact fingers S disengaged from contacts N.; This cuts the starting winding out of circuit and also the series magnet' P. The

motor will now continue to operate with the two running windings Vin parallel. The motor may be disconnected by pressing button 30 inwardly, which will open switch J and disconnect thc shunt electromagnet L, thereby permitting the Shaft 44, to rock and the fingers T to be moved out of engagement with the contacts N.

'lt is obvious that various mechanical and electrical changes may be made without departing from my invention. A time control check may be substituted Jfor the se.- ries electromagnet P, However, the Varions changes which may be resorted to Without departing from my `invention will be apparent from the description and the subjoined claims. A

Vhat I claim is:

1.. The combination with an induction :notor having aplurality of running windings and' a starting winding of a switch structure comprising a starting set of contacts connected thereto whereby when said set is closed less than all of said running windings will be connected in parallel and said starting windingl will be connected in circuit, the remaining running winding being in open circuit, means to manually operate said set of starting contacts as a unit, a running se't of contacts whereby to connect all of said running windings in parallel and to place said starting winding in open circuit, and a time delayed means for automatically' closing said running contacts as a unit.

2. The combination with an induction mo- A tor having a plurality of running windings and a starting winding of a, switch struc- ,ture comprising a starting set of contacts connected thereto wherebywhen said set is closed less than all of said running windings will be connected in parallel and said starting winding will be connected in circuit, the remaining running winding being in an open circuit. means to manually operate saidl set of starting contacts as a. unit, a running set of contacts whereby to connect all of said running windings in parallel and to placel said startingv winding in open circuit. a constant current electromagnct for closing said running contacts kas a unit arranged to be placed in circuit by closure of said starting set of contacts. and means to delay closureof said running contacts.

3. The combination with an induction motor having a plurality of running windings and a ystarting winding of' a switch structure comprising a starting set of contacts conncctcd thereto whereby when said setis closed less than all of said running windings will bc connected in parallel and said starting winding will bc connected in lll) circuit, the remaining running winding be ing in an open circuit, means to manually operate said set of starting contacts as( a unit, a running set of contacts whereby to connect all of said running windings in par-l allel and to place said starting winding in open circuit, a constant current closure electromagnet for closing said running contacts as a unit arranged to be placed in circuit by closure as a unit arranged to be placed in circuit by closure of said starting set of contacts, an opening electromagnet in series with said starting winding, a differential armature orsaid electromagnets, and means connecting said armature and said ruiming set of contacts to operate the latter.

4. The combination with an induction motor having a plurality of running windings and a starting winding of a switch structure comprising a starting set of contacts connected thereto whereby when said set is closed less than all of said ruiming windings will be connected in parallel and said starting winding will be connected in circuit, the remaining running winding being in an open circuit, means to manually operate said set of starting contacts as a unit, a running 'set otl contacts whereby to connect all of said running windings in parallel and to place said starting winding in open circuit, a constant current electromagnet for closing said running contacts as a unit arranged to be placed in circuit by closure of said starting set of contacts, means to delay closure of said running contacts, and manually operable means to disconnect said electromagnet from circuit.

5. The combination with an induction motor having a plurality of running windings and a starting winding of a switch structure comprising a startingset of contacts connected thereto whereby whcn said set is closed less than all of said running windings will be connected in parallel and said starting winding will be connected in circuit, means'to manually operate said set of starting contacts as a unit, a running set of contacts whereby to 'connect all of said running windings in parallel and to place said starting winding in open circuit, a constant current closure electromagnet for closing said running contacts as a unit arranged to be placed in circuit by closure of said starting set of contacts, an opening electromagnet in series with said starting winding, a differential armature for said electromagnets, means connectingr said armature and said running set of contacts to operate the latter, and manually operable means to disconnect said closure electromagnet from circuit.

6. The combination with a single phase induction motor having a pair of running windings and a split phase starting winding of a switch structure comprising a starting jinduction motor having a pair o runniig windings and a split phase starting win ing of a switch structure comprising a starting set of contacts connected thereto whereby when said setris closed one of said running windings and said starting winding wil be connected in parallel across the line, the remaining running winding being in an open circuit, means to manually operate .said set of starting contacts as a unit, a running set of contacts whereby to connect both of said running windings in parallel and to place said starting winding in open circuit, a constant current electromagnet for closin said running contacts as a unit arrange to be placed in circuit by closure of said starting set of contacts, and means to delay closure of said running contacts.

8. The combination with a single phase induction motor having a pair of running windings and a split phase starting winding pf a switch structure comprising a starting set of contacts connected thereto whereby when said set is closed one of said runnin windings and. said starting winding wiligbe connected in parallel across the line, the remaining running winding being in an open circuit, means to manually operate said set of start-ing contacts as a unit, a running set of contacts whereby to connect both of said running windin s in parallel and to place said starting winding in open circuit, a constant current closure electromagnet for closing said running contacts as a unit arranged to be placed in circuit by closure of said starting set of contacts, an opening electromagnet in series with said starting winding, a differential armature for said electromagnets, and means connecting said armature and said running set of contacts to operate the latter.

9. The combination with a single phase induction motor having a pair of running windings and a split phase starting winding of a switch structure comprising an electrical connection common to each of said windings and one side ofthe line, a starting set of four contacts, one being connected to the other side of the line and one to each winding, a manually operable' starting contact finger for engagement with said, contacts whereby the line contact, a running winding contact, and the starting winding contact are interconnected the remaining running Winding being in an open circult, a runnin contact finger for engagement with sai contacts whereby the line contact and both running winding contacts are interconnected. and the starting winding contact is in an open circuit, and a time delayed means for closing said running contact finger.

10. The combination with a single phase induction motor havin a pair of runnin windings and a split p ase starting win ing of a switch structure comprisin an electrical connection common to eac of said windings and one side of the lineLa starting set of four contacts, one being connected to the other side of the line and one to each winding, a manually operable starting contact fin er for engagement with said contacts where y the line contact, a running winding contact and the starting winding contact are interconnected the remain,y ing running Winding being in an open circuit, a runnin mentl with sai contacts whereby the line contact and both running Winding conI tacts are interconnected and the starting- Winding contact is in an open circuit, a con.- stant current closure electromagnet for closing said running contact finger arranged to be placed in circuit by closure of said starting contact finger, an opening electro-I magnet in series with said startin winding, a differential armature for sald elec contact finger for engage the other side of the linevand one to each Winding, a manually operable starting con- .tact fin er for engagement with said contacts W ereby the line-contact, a running Winding contact and the starting Winding contact are interconnected., the remaining running Winding being in an open circuit, a running contact finger for engagement with said contacts are interconnected and the starting Winding contact is in an open circuit, a constant currenty closure electromagnet for closing said running contact finger arranged to be placed in circuit by closure of said. starting contact finger, an opening electromagnet in series with said starting Winding, a differential armature for said electromagnets, meansconnecting Said armature' and ,said running contact finger to operate the latter, and manuall operable means to open the circuit inclu said closure electromagnet.

in n Witness that I claim the foregoing I have hereunto subscribed my name this 29th day of March 1923.

CHAizLEs H. WELLINGTON.

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