US1883773A

US1883773A - Electromagnetic relay

Info

Publication number: US1883773A
Application number: US538058A
Authority: US
Inventors: Erickson John
Original assignee: Associated Electric Laboratories Inc
Current assignee: Associated Electric Laboratories Inc
Priority date: 1931-05-18
Filing date: 1931-05-18
Publication date: 1932-10-18
Anticipated expiration: 1949-10-18

Description

Oct. 18, 1932. J. ERICKSON I ELECTROMAGNETIC RELAY Filed May 18, 1951 Inuenlczr- Jahn Erickson value.

Patented oct.. 181932 UNITED STATES llaTlaziaT oFFlci;

JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOB, Bf MESNE ASSIGNIEN'TS, T0

ASSOCIATED ELECTRIC LABORATORIES, 'INCWOF CHICAGO, ILLINOIS, A CORPORA- TION F DELAWARE ELECTROLIAGNETIC RELAY Application led lay 18, 1931. Serial No.`538,05 8.

This invention relates-in general to electromagnetic relays, but more particularly to relays which are operated by alternating current, and the principal `obj ect of the invention is to design a new and improved alternating current relay, which will be extremely sensitive and eiicient in operation, will control a larger number of contact springs with better contact ressure between the springs, and besimple 1n constructionl and economical to' manufacture.

In alternating current relays, when the relay winding'is energized the armature has a tendency to chatter or hum due to the current in the coil passino' through zero `potential This may effect the contact springs controlled by the armature and result in un- .desired operations. To' a`void this .chattering of the armature, vvarious means have been cdevised to provide a secondary orholding flux in the magnetic circuit of the relay whlch is out of phase with the primar or main flux of the relay soas to maintain t e armature in its attracted position at the time that the main f flux ceases to ilow due to the cycles of alternating current being at zer'o potential. This l is commonly known as pole shading and lone method of accomplishing this is to rovide a copper ring or short-circuited win ing on the armature end of the core.

It is an object of the invention to design a relay having new .and improved meansv for providing a displacement ofthe main lux flowing through the relay, and in accordance with this object a particular feature of the" invention resides in providing a novel shading coil which in general takes the form of a short-circuited winding or ring of electric current conducting material enclosing a portion of a pole face or core of the relay.

A particular feature of the invention resides in providin a plurality of washers made of copper w ich perfornrthe function ofYrint-roducing a displacement of the main flux flowing through the core of the relay, and

depending upon the number of washers assembled together theamount of this displacement of the iux may be adjustable.

Another feature of the invention is directed to a novel mounting late and its arrangement for supporting t e contact spring sets, the armature, and the relay as a unlt.

laminations of the. magnetic structure of the relay and at the same time securely supporting the armature and spring mounting plates to the structure. l

The above objects and features and others will be apparent from the following detailed description, which, together with the-sheet of drawings, illustrates a preferred embodiment of the invention.

In the accompanying drawing, Fig. 1 illustrates in elevation a relay embod ing the invention; Fig. 2 is a rear view o'gthe relsy taken from the left-hand side of Fig. 1 ig. 3 is a perspective view showing only the laminated core and the mounting plates, the other parts of the relay being removed; F lgl. 4is a top view of the relay; while Fi 5 s ows a perspective of a pair of pole shaders or short-circuiting copper rings.`

Referring to the drawing, the relay lcomprises the coil or winding 5 wound between An additional feature of the invention rei sides in the means lfor holding together the a pair of insulated spool-heads 6 on each end,

as seen inA Fi v1.- Al-preferred method of holding the wlnding of the coil is to provide an insulated or bakelite spool with which apair of legs 7 and 8 )oined together at one a end. This magnetic member 1s preferably constructed of silicon iron and consists of af plurality of thin pieces of laminations bound together to form"l a unitary structure. The coil wound upon the spool 6, is placed` over the leg 7 of the magnetic member and in `this way itserves as a core for the coil.

A pair of substantially Z-shaped non-magnetic supporting

plates

9 and 10 are mounted on each side of the leg 8 of the magnetic member. The mounting plate 9 he a a turned over extension 11 for lsupporting one end of the armature While at the bottom of j the plate 9 a turned over portion 13 servesas a means for supporting the complete relay on a suitable base. The plate also has a turned up ear portion 12 for supportingthe armature, and at the bottom asimilar portion such as 13 on plate 9 for supporting the relay. The

plates

9 and 10 are secured to the

legs

7 and 8 at the bottom of the coil by means of a pair of rivets ltextending from each 4of the extensions 13 directly through the laminated pieces of` the core to .the opposite side where they are riveted together. At the opposite top end of'each ot the plates 9 and 10 a pair yof rivets 16 are provided which extend from extension 11 of the plate 9 through the laminat-ions of the leg 8 to the projection 12 where the are Jriveted together. Additional rivetsj15 on the leg 7 of the mag'- netic member are provided in order to secure the laminations together on the leg 7.

With the foregoing structure it'is seen that the laminations andthe

plates

9 and 10 are secured together by the rivets 14 on the bottom side of the U-Shaped magnetic member,`

and at the top `by the rivets 16`to form a solid unitary structure.

j The leg 7 of the core is provided at its-end with a'pair of projections'or pole-pieces 17 and 18 separated by a slot so that one or more copper rings 19 and 20 may be-placed on lthe leg 7 surrounding this projection 18. In order to securely hold the copper rings 19 and 20 onto the leg 7, the last two laminations on each side of the leg 7 are bent lover on' the top vof the ring 19. This prevents dislodgment of the rings and at the same time securely holds the coil 5 onto the leg 7.v The lcopper rings 19 and 2O then lie directly upon the top edge of the insulated spool-heads 6.

The armature -is provided at its vend with a brass residual pin 26 which strikes against the end of pole-piece. 18 to prevent sticking of the armature 26 on the core when the coil is deenergized. The armaturev25 is ypivoted by pin 27 to the supporting member 28 which in yturn is secured by

screws

29 and 30 in the extensions 11 and 12 of the supporting plates 9 and 10.v The

screws

29 and 30, when loosened permit the supporting member 28 to slidevup or down in the slots 31 and thereby adjust the armature stroke -with res ect to the ends of the pole pieces t' 17 and The armature 25 is provided on each side with contact controlling arms 32v Aposition of the armature. The contact spring sets 35 in addition to suitable soldering *tags for coil5 are secured by screws 37 threaded into the sides of mounting

plates

9 and 10. In order to support the relay as a unit on a suitable mounting plate, the screw holes 21 on the

plates

9 and 10 are provided.

It will be seen that with the foregoing construction ofrelay, when the winding of coil 5 is energized by a suitable source of alternating current, a magnetic Hux is generated for operating the armature 25 which extends over apath including the

laminated core legs

7 and 8, armature 25, and the pole-pieces 17 and 18 at the end of leg 7 This constitutes the main lux which flows through the relay at each. cycle of the alternatingl current. This main lux will induce a current flow into the copper rings 19 and 20 which lags or is the copper rings 19 and 20 will cause a holding flux tofollow a path extending from pole-piece 17 through armature 25, back over pole-piece 18 and across the 4end of leg 7 to pole-piece 17 again. 'llhis holding flux is of sufficient strength to maintain the armature 25 in its attracted position between each cycle of the alternating current. It is therefore seen that at zero current value through the c oil the holding iiux generated due to the current induced in the copper rings 19 and 2O holds vthe armature against the two polepieces 17 and 18 of the core 7 to maintain it in v a stable position, and prevent it from fluttering in synchronismwith the cyclesof altrnating current,'so that the contact springs 35 will remain operated as long as the alternating current is connected to the coil 5.

When the relay is required to be operated in a circuit which provides a source of alternating current of a low frequency a condition exists in which-it is diiiicult to maintain the armature in an attracted position during the interval that the current is passing through zero potential value. This occurs due to the fact that as the current builds up in the coil 5 in the first half of its cycle the armature is not immediately attracted but only when the -lux is strong enough'to pull it down upon the pole-pieces 17 and-18. Similarly in this half cycle as the flux decays, the armature will retract before the flux has fully ceased to flow and .before the current is at zero potential value. `It is therefore seen that before the opposite cycle of current. creates a flux inthe opposite direction anap- .ireciable time interval exists during which the armature will not remain o erated at the lo w frequencies.6 Toprovide or this an addltional number of copper washers or rings 19 and 20 are placed on thepole-piece 18 in order to create a greater holding flux out of phase with the main flux through the relay and maintain the armature attracted vand* stable between each cycle of the alternating current.

In instances Where the relay is to be operated by alternating current of high frequencies a lesser number of

copper washers

19 and 20 are required because the interval between each cycle of alternating current during which the armature is held attracted isl not as long as on lowfrequencies. l For all ordinary. purposes on frequencies .such as used in the telephone arta pair of copper `washers is all that is required.

p It is 'desired in certain instances that a greater number of spring combinations such as be operated by the karmature vfrom that shown. When this occurs it will be appreciated that upon o eration of the contact sprin sets 35 consi erabletension will be store inthe armature springs so that when subsequently the current 'through coil 5 passes through zero potential value it will require considerable lforce to maintain the armature in its attracted position. In order vto induce a'greater flow of flux. in the holding magnetic circuit for holdingthe armature attracted in this instance, additional copper rings or washers, such as 19 and 20 may be piled up on the pole-piece 18 in order to create a larger amount'of ux from the main flux flowing through the magnetic circuit.

Similarly when a smaller set of spring combinations are used on the relay a less number of copper rings may be provided. This provides a convenient method of adjusting the lag in the armature when desired.

Due to the fact that the magnetic circuit is completed over the laminated U-shaped member which is made of silicon iron, a very eilicient magnetic A circuit is provided thatis free of any retarding eddy currents, provides an efficient ath for the flux to How and also be powerfu enough to operate the armature 25 to control a large number of contact spring sets.

hile only one embodiment of the invention has been shown and described, it is not desired to be limited to the exact arrange- .ment shown and described butalso those modifications that may fall Within the spirit porting the armature of the relay in operative relation to the end of said first leg, means on the other end of said supporting members for mounting the relay as a unit, means on each of said suporting members for mounting a set of contact springs controlled by the armature, and means on said supportingmembers for adjusting the movement of the armature against the first leg of the relay. l

2. In an electromagnetic relay, a U-shaped laminated magnetic structure havinga winding on one leg,a` non-magnetic supporting plate on each side of the other leg of the magnetic structure, means on opposite ends of. said supporting plate for securing the supporting plates and the laminations of the magnetic structure together, means on one end of said supporting plates for securing the armature of the relay in operative relat-ion to the other leg of the magnetic structure, means on the other end of said supporting plates for mounting said relay, means between the ends of said supporting plates for mounting a set of contact springs controlled by the armature, and means on said supporting plates for adjusting the movement of said armature against the Winding leg of the magnetic structure.

3. In an alternating current relay, a U- shaped magnetic structure having a Winding on one leg, separate non-magnetic supporting plates on each side of the other leg, means on one end of said supporting plates for connecting them togethei` across the leg of the magnetic structure to form a support for the armature of the relay so that it will be in operative relation with the end of the other leg', means on each of the ends of said supporting plates for securing them to the magnetic structure, and means between the ends of each of the supporting platesl for mounting a set ot Contact springs controlled by the armature. v 4. In an alternating current rela-y, a U- shaped magnetic structure having a Winding on one leg, a pair of non-magnetic supporting plates on opposite sides of the other leg, means on one end'ot said supporting plates tor mounting the armature of the relay so that it is in operative relation With the other leg of the structure, non-magnetic Washers on the Winding leg arranged to provide a magnetic flux displayed in phase relatively to the main fiux in the magnetic structure for maintaining the armature attracted to prevent chattering thereof when the current through the Winding passes through zero potential, and means on said non-magnetic supporting plates for mounting said relay as a unit and for. securing sets of contactsprings thereon controlledby the armature. Y

5. In a-relay having a U-shaped magnetic structure, a Winding on one leg thereof, a pair of non-magnetic supporting plates on v support for the armature of the relay, said projections connected together and bridging the ma netic leg of the structure to form an adjnsta le support for varying the movement ofthe armature against the other leg of the structure, means on the other .end of said nonmagnetic supporting plates for securing said relayto a mounting plate as a unit, means intermediate the ends of the supporting plate for mounting sets of contact springs controlled by the armature, and means on each end of said supporting plates for securing them to said magneticstructure.

6. An electromagnetic device having an armature and a magnetic structure comprising two legs2 an 4energizing winding on onel leg, a mountlng member on the other leg means on one end of said mounting member for supporting the armature in operative'relation to sald first leg, means on the opposite end of said mounting member for supporting the device as a unit, and means on said mounting memberforadjustin the movement ofJ the armature against the rst leg of the relay.

7. In an electromagnetic device having an armature, a magnetic structure having a pair of legs, an energizing winding on'one leg,

forming a ysupport for the armature and connected together across said leg, means on said armature support for a justing the movement of the armature against the winding leg, means on the other end of said supporting plates for supporting said device as a unit, and a pluralit of shadin coils supported around the endyof posite said armature and on top of said windmg.

In witness.whereof, I hereunto subscribe my name this 14th dat?1 of May, A. D. 1931.

' @Y OHN ERICKSON.

mounting plates on each 'side ofy the other of said legs, means for vconnectingsaid plates together across said other leg to form a pivot for the armature and so that it extends o po- 'site the end of said first leg, shading coi on said first leg opposite said armature, and means on said mounting plates for supportn ing said device asv aunit.

8. In an electromagneticv device, a mag- `netic 'structure comprising a pair of legs joined together at one end, an.- energizing wmdmg on one of said legs, an armature-on the other of said legs and extending in operav tive relation to the first le supporting plates on said otherleg arrange to pivot said armature and support said device as a nit, shadin coils on said first leg opposite the moving en 'of said armature, and means for holding said shading coils and the energizing winding together on said first leg.

v9. In an electromagnetic device havinganv armature and a magnetic structure comprising two legs, an energizing winding. on one'of said legs, means for supporting the armature n the-other of said le tion to's'aid first leg, s ading coils on said in operative relai first leg, Aand means on said first leg for "l clam ing said shadin coils and energizing win mg together 'on t e leg.

10, In an electromagnetic device havingan armature, a `ma etic` structure having two legs oined toget er on-one end, an energizing win ing on V'one leg a pair ofhsupporting plates on opposite sides ofthe ot er leg, pro- )ections on one end of said supporting plates the win ing leg opf