US1696615A

US1696615A - Electromagnet

Info

Publication number: US1696615A
Application number: US189878A
Authority: US
Inventors: Trombetta Panfilo
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1927-05-09
Filing date: 1927-05-09
Publication date: 1928-12-25
Anticipated expiration: 1945-12-25

Description

Dec. 25, 1928;

P.- TROMBETT A ELEGTROMAGNET Inv@ futon PahFlo Tron betta. |95 M l His Attorngg Patented Dee. 25,1928.,

UNITED STATES PATENT. OFFICE.

PANFILO` 'momen-MA, or SCHENEOTADY, NEW YortignssreNon 'ro GENERAL ELEO- TRIO COMPANY, A CORPORATION or vNew Yonx.

ELEOTROMAGNET.

,application med Hay 9, 1927. Serial No. 189,878.

ll`he..,present invention provides ,an improved form of electromagnet particularly suitable for alternating current service, al though certain features of the invention are equally advantageous in direct current service.

One of the princi al Objects of the mvention. is to provide an improved A construction and arrangementofI the magnetic circuits and windings of the clectromagnet whereby the power and efiicicncy of the electromagnet in both alternating and direct current service may be materially increased over that ordinarily obtained.

A further object of the invention is to construct the electromagnet so that it readily may be mounted or supported iny many di'erent ways and connection made with the movable magnetic member to either pull or push a switch, valve, or other device to be operated thereby.

Another object of the invention is to provideV an improved mounting for the magf netizing windings `of the electromagneaJ arrangedso that the windings are lirmly fscrured inthe proper operating position and still may be easily -and readily assemf bled and disassembled without the use of any clamping screws, bolts, or'the like.

A still further Object of the invention is to render the operation of the electromagnet inalternating current service' as quiet and free from vibration as possible with the minimum consumption of energy in the pole shading windings.

- Other Ob 'ects and advantages of my invention will appear from the following description f the accompanying drawing showing a preferred form of electromagnet embodying the several .improvements of the iuventionset forth in the appended claims. In the draw-ing, Fig. 1 is a perspective view of my improved electromagnet with thc'various 'parts assembled in cooperating ..1'elation; Fig. 2 is a perspective View `of the ,electromagnet with -the magnetizing windings removed to show the constructional details of the frame and the movable plunger vforming the magnetic circuits of the e ectromagnet, as well as the pole Shading winding which is associated therewith for alternating current service; Fig. 3 is an enlarged `fragmentary view showing more clearly the relative location of the pole shading winding with reference to the cooperating magnetic members ofthe electromagnet; Fig. 4 is a perspective view of the magnetizing windings of the electrof magnet and the mounting elements theretor;v while Fig. 5 shows certain guide elements that may be employed in a modified construction of the electromagnet shown in Fig. 1.

Referring to Fig. 1, the electromagnet comprises essentially the magnetic frame 10, the movable magnetic plunger 11, and the magnetizing windings 12. In order to permit eiicient'operation with alternating curl in the drawing. As more clearly shown in f Fig. 2, each of the superimposed laminations constituting the frame 10 is formed in substantially the-shape of a rectangle so as to closely encircle the magnetizing wind- 'ing 12 except for the cut-away portion in one side of each lamination forming the Opening 13 through which the plunger 11 operates within the magnetizing windings 12. fThe rectangular frame laminations are clamped in alignment between the opposing pairs of angle supporting pieces 14 which are held securely together by the rivets 15 with the spacin members 16 interposedl between the vang e supports and the laminations. Theftwo opposing angle supports 14 at the end of the magnetic frame having the Opening 13 therein bridge across on `either side of this opening and serve tov extending from the plunger 11. Moreover, these angle supports are arranged with the outstanding flanges thereof substantially flush with the outer edge of the laminations. This provides' a broad substantial base upon which the electromagnet may be mounted. The angle supports at the other end of the frame are disposed with the outstanding flanges thereof in substantial alignment with the inner edge of the laminated frame instead of the 'outer edge; Itwill be observed that each ofthe angle supporting pieces is provided with suitable spaced apart holes to permit mounting of the electromagnet upon y"any one or more of these angle supports. YThe rivets 17 serve to hold the frame laminations firmly together intermediate tlie angle supports 14. Preferably, the rivets and 17 are hollow and slotted 0 along one side and are located in open slots formed in the outer.,edge Aofthe laminations constituting the frame 10, as this construction effectively prevents the production of eddy currents in the rivets in alternating `current service, hereby increasing the eiciency of the electromagnet.. I `In the preferred form illustrated in'Fig. 2 the laminations forming the movable magnetic member or plunger 11' are rounded at lone end and are provided With opposing lateral extensions at the other end inthe form of a sector. Thus When superimposed and secured together bythe rivets 18, these laminations form aplunger having al body 'portion 19 of rectangular cross section adapted to reciprocate freely but Without possibility ofrrotation in the opening 13 in the frame 10v and' presenting a convex cylindrical surface atfthe end 20 with the lateral projections of the laminationsforming an enlargeddiead' 21 at the other end. The Vrivets 18 preferably are located along the axis ofthe plunger 11 While at theenlarged headof the plunger the laminations are secured together by rivets `22 located'in open slots in the outer edge of the head in substantially the same manner as the

rivets

15 and 17 of the frame 10. f l

To cooperate with the convex end of the "plunger 11, the side of the frame 10 opposite the opening 13-is provided with an oppositelyrounded or concave surface 23. As showin,.t he surface 23 is formed at the end of,the polar projection 24located on the 'inside. of the frame,10\ opposite the opening 7.13 'so as to extend a short distanceswithin the core space of the magnetizino' windings 1'2. The coivexly rounded end of the lunger 11 and the'concavely rounded sur ce 23 of the `frame 10 thus constitute complementary engaging surfaces When the plunger 11 'is operatedfto the attracted position within 1' the core spaceI of the windings 2.

These complementary engaging surfaces are'considered an important featurevofthe present invention and although the co- `rmagnetic members readily nests within, and

is enveloped Vby the complementary surface of the cooperating magnetic member.

Furthermore, for alternating current service -a pole shading Winding is located Vad-l Vjacent the engaging surface of one ofthe cooperating magnetic members in order to render the electromagnet quiet and as free from vibration as possible. In accordance with the present invention the pole shading operating magnetici-plunger and frame are Winding is mounted on the magnetic mem- Y ber presenting the surface which' envelopes the complementary engaging surface of the cooperating magnetic member and located closely adjacent to this surface. Thus in the preferred form o electromagnet illustrated the pole shading winding 25 islocated in slots formed in the concave cylindrical surface 23. As shown in Fig; 3, this location of the pole shading Winding 25 permits a portion of the end of the plunger 11 to pass Within, and be encircled by, the pole shading theplunger is in the attracted position. As a result `of the complementary enveloping and enveloped shapes of the engaging sur faces of the plunger and frame and the lo- Winding by the amount indicated as a, when f cation l,of the pole shading Winding on the enveloping surface, the operation ofthe electromagnet with alternating'current 1 s rendered quiet and practically vibrationless with a minimum expenditure of energy inV the-pole'shading Winding. I, l l

As clearly shown in Fig. 2, the pole shading Winding is formed by the tWo rivets 25, preferably of iron or other resistance ma-y terial, which are located inopen slotsy in the surface 23 and electrically connected to-I gether at their ends through the outer laminatins Lforming' the frame 10. In order to complete the electrical lcircuit, the ends of the rivets 25 are welded to the outer laminations, thus providing a reliable conducting junction betweenrthe ends of the rivets l and the outer laminations. Moreover, the pole 'shading winding formed by the, rivets 25 is symmetrically' located with reference to the engaging surfaces of the projection f ,24 -and of the plunger 11 so as to balance.

the outV of phase magnetic forcesset vup by the pole shading winding. 'This materially aids in maintaining the plungerl 11 in magnetic vequilibrium and 'thereby' avoids noise .gud vibration in the`l electromagnet.

When it is desired to further increase the iso the curved end of the plunger 11 into nest' ing alignment with the enveloping surface 23 are augmented and thereby insure that the plunger is held in both magnetic and me chanical equilibrium. It will be understood, however, that the slot 26 serves simply to amplify themagnetic and mechanical alancing forces inherently obtained with the magnetic structure as previously de scribed and hence may be omitted if desired. The centrally located rivet 27 serves to hold the laminations in the projection 24 firmly together against the hammermg action reultin from the repeated engagement of thef 1).un ed endof the plunger 11 with the nomplementary rounded surface 23, while the fpole shadingwinding rivets 25 having their ends welded to the outer laminations serve effectively to hold the laminations together at the extremities of the convex surface 23,

The' length of the body portion 19 of the plunr 11'Qis made such that when the roun ed end 20 en ages with the'complementary curved su ace 23 of the frame 10, the opposing project-ions forming the en larged head 21 of the plunger are brought just short of abutting engagement with the opposing legs of the rectangular frame 10 defining the ,openin 13. This provides .two practically clos. circuits of laminated magnetic material in multiple relation for the flux of the operating windings 12 when the plungerl 11 bridges -the gap between the polar pro'ection 24 and the legs of the rectangular rame on either side of-the 'opening 13. Consequently, practically all of the magnetizing flux is localized in the multiple paths of the laminated ma netic structure formed by the plunder an frame of the electromagnet, and amount' o flux passing betweeen the frame 10. and the plunger 11 through thesolid angle pieces 14. This construction permits ot a relatively large clearance between the body of the plunger 11 and the ends of the' framelaminations defining the opening 13.

Hence, rugged and substantial bearing guides for the plunger 11 may be placed in the opening 13, as later described, lwithout appreciably increasing the reluctance of the substantially closed magnetic circuit formed by the enlargedv head 21 of the plunger or adversely affecting the eiciency of theelectromagnet, or the magnetic and mechanical balance ofthe plunger 11.

To vpermitready attachment of a link, lever, or other connection to be operated -by there is no appreciable for use therewith.

the plunger 1l, the laminations constituting the plunger head 22 are formed to provide a central slot 28 with thc hole 29 arranged to transversly intersect the slot 28. Thusfby forming a corresponding hole fin the link, or other connection to beoperated by the plunger, a. good connection readily may be made by means of a cotter pin, bolt or other suitable fastening. In addition, the two arms 30 and 3l are secured on opposite sides of the body of the plunger 11, preferably by means of separate rivets 18 in order that the operating force of the plunger may be transmitted through the ends of the arms extending beyond and st-raddling the opposite side of the frame 10, as shown in Fig. 1. The spacers 16 serve to maintain the angle pieces -14 a suicient distance away from the sides of the magnetic frame 10 to permit the arms 3'() and 31 to freely slide between the angle supports and the frame. In this way the angle supports 14, the spacers 16, and the frame 10, form guidewlays of large bearing surface for maintaining the 'plunger 11 andV the

arms

30 and 31 in proper operating alignment with the device to be operated by the electromagnet. l

With the construction illustrated in Figs.

1 and 2, the entire electromagnet readily nection to be operated by the plunger of the eleetromagnet may be either pulled by connection with the plunger head 22 or pushed by connection with the outer ends of the

arms

30 and 31. The connection with the outer ends-of the

arms

30 and 31 may be made by any suitable means such as the bolt 56 pass'-` ing through the holes 32 with the spacing collar 57 interposed between the ends of the arms as illustrated in Fig. 1. It will be cvident that this construction'adapts the electromagnet for a wide'variety of applications with a minimum of restrictions in the manner of mounting and establishing the-operating connections.

While any suitable form of magnetizing I -ing winding construction and mounting illustrated in Fig. 4 is particularly adapted In this construction the magnetizing windings preferably1 are placed on two cooperating

spools

33 and 34, each of which may be formed of moulded insulating material. y l

Itwill be observed that the spool 33 is of substantially rectangular form with space `for receiving the layers of the windings 12 between the

end flanges

35 and 36 and ajcentrally located winding barrier 37. Thus the body of the spool provides a core space 38 of the precise shape frequired to permit therectangular body 19 of the plunger 11 with the pusher arms and 31 attached thereto to operateA loosely and freely in relativey close proximity to the magnetizing win ings 12. v

`The end liange 36 has a slot 39 formed in the outer face thereof,-while the end flange is pri'ivided with a corresponding projection extending from the outer face tllercoi.

Theconstruction of the winding spool 34'" is identical with that of the spool 33 and the arrangement is such that the projection 40 on the spool 33 snugly nests within the groove 39 of thc Winding spool 34 when the spools are properly brought together. The

outside groove 3S) ot the spool 33 and the` outside projection 40 of the spool 34 are arranged to be used in the following manner in mounting the inagnetizing windings withinv the magnetic ramelO4 of the electromagnet as shown in F ig. 1.

Two

guido pieces

41 and 42 of angular shape and of suitable bearing material, such as bronze or bakelite, are arranged to.

fit into the groove 39 on opposite sides of the core space 38 with the upstanding portions 43k and 44 of the guidesextending over the ends ot' the laminations ot'- the frame -10 deining the opening 13 to serve as guides for the plunger 11. The

spring members

45 and 46 and the

channel members

47 and 48, which latter are of insulating material, co-

- operate with the outside projection 40 o'n the spool 34in the mounting of the magnetizing windings inthe electroinagnet frame 10, in the manner indicated in Fig. 1.

In assembling the

spools

33 and 34 with the magnetizing windings 12 located thereon inv i theframe 10, the insulating channels 47 and 48Y first are placed adjacent to the polar projection 24 so. as to extend over the'opposing angle supports 14 and the frame lamina-tions secured therebetween.- The springs 45 and-A 46, having an'oset at their central portions Y to form a yoke fitting snugly over the insulating

channels

47 and 48, then are placed in position. In this way each spring is maintained out of electrical contact with both the laminations and the angle supports and thus avoids forming a short circuited turn encirclingthe llux projection 24.

The endsof the

springs

45 and 46 when thus, assembled over the channels as shown in Fig. 1 are spaced so as to engagefirmly .with the sides of thevprojection 40 as the winding spool 34 is inserted over the .polar projection 24` of the frame .'10A with the plunger `11 withdrawn. The guide pieces 41 and 42 :treff-then placed with theportions 4?.

and-44 lying over the ends of the laminations of the corel() at the opening 13. By compressing' the

springs

45 and 46 the windingspool then may be inserted between the passing through the polarl right hand end of the spool' 34 and the inside of the right hand angle supports 14 and moved into position to engage the projection 40 Awith the slot 39 and the slot 39 with the

guides

41 and 42. Thereupon the winding spools 33' and 34 are held firmly pressed against the right hand end of the electroniagnet frame 10 and the right hand angle supports 14 by the springs 47 and 48.y 'llhe guide '

members

41 and 42 interlocking with the-slot 39 positively prevent lateral displacement oi the ri glit hand 'end of the winding while the ends of the

springs

45 and 46 engaging with the projection 40 'likewise lock the left hand end of the windings against lateral displacement.

erating position with practically no possi- Iii this Way the windings are mounted in the proper opbility` of chaliingv or displacement of the windings due to extraneous sliock'or vibrationduring service, all witho'ut the use ot clamping screws or bolts whichmight loosen during operation.

The plunger 11 jwith. the

pusher arms

30 and 31 attached then may be inserted through the opening 13sin the'core 10 to re ciprocate within the

openings

38 and 38 in the inagnetizing windings. The pusher arms 3,0 and 31 straddle the core laminations ot the polar extension 24 and pass freely between the angle supports 14 as previously described. With the arms 3 0 and 31 secured together yat their ends by the bolt 56 as shown in Fig. 1, it will be evident that the spools carrying the magnetizing windings 12 are electively locked in place.

While I have illustrated and described the inagnetizing winding as carried on two sep aiate interlocking spools, it should be understood thatvthe winding may be ca r' ied on a single spool if desired and the other spool used Vsimply to interlock the winding rpool in position in the frame. Moreover, in cas inov the concave surface 23 isrlocated flush willi the frame laminations opposite the opening 13 only a single winding spool is required. In this case the single spool may hc piovided with a slot in the outer face of one end tiange and a corresponding projection on the outer face of the opposite end flange which serve `to lock the single spool in position ,in the frame in exactly the same manner as' dcscribed in. connection with the two spool I 55, cations therein may be made by those skilled tions remain firmly secured together by the rivets 18. With the arms'V 30 and 31removed the,operativeconnection then is made with the plunger 11 solely through' the slot'28 and the hole 29 formedinthe laminations ot' the head 22. In this case the space reserved. for the

arms

30 and 31 is 'occupied by the guides 49 and 50 in order to maintain the plunger 11 in' proper operating alignment with the frame 10; rlhe guides 49 and-50 may be formed. of a suitable bearing material such as bronze, or a tough material such as bakelite, as desired. With the

pusher arms

30 and 31 eliminated, the guides-49 and 50 are inserted through the opening 13 on either sidev of the 4polar projection 24 after the magnetizing winding

spools

33 and 34 are assembled in the manner previously set forth. The holes 51 and 52 i`n the guides y49 and 50 are arranged to register with the holes 53 located inthe angle supports 14 so that a suitable securing pin, such as the Cotter 54, may be inserted to lock the guides `in position. The upstanding' shoulders 55 formed at the right hand ends of the guides 49 and 50 are arranged to lit in the 'recess formed on either side of the projecting

portions

43 and 44 of the

guidepieces

41 and 42. Thus with the guides '49 and 50 secured in place, the magnetizingjwindings again are effectively locked in their proper operating positions. f

Although not shown in the drawing, it will be evident that `the magnetizing windings 12 may be energized and controlled in any desired way;I for example, the portions of the windings on the two

spools

33 and 34 may beiv connectedeither in series or in multiple as desired, Furthermore, the.

magnetizing winding 12V may be divided intol different portions, one arranged to operate they plunger .11 from the unattracted to the attracted position, and the other solely for Yholding the plunger' 11 in the attracted position. The particular manner in which the magneti'zing Windin s mayl beenergized and controlled is descri ed and claimed in 'my copending application, Serial' No. 206,- 466, filed July 18, 1927, and hence no further' description thereof is deemed necessary.

While I have illustrated anddescribed the improvements of the present invention in a preferredv formof electromagnet, it will be understood' that various changes and modifiin the art without departing from the spirit rangement may and scope ofthe' invention. Furthermore,

. while the construction and arrangement ofl tha magnetic-lcircuits and the magnetizing i andpole shadingwindings of the electro magnet describedfheretofo're are particularlyl f 1 advantageous and efficient when the electromagnet is energized with'I alternating lcurrent, still the identical construction and ar beused indirect current service with materially increased power and eiciency of the electromagnet.

What I claim as new and desire to secure by Letters Patentjof the United States, is:

'1. An alternating current electromagnct comprisingzmagnetizing windings, relatively movable magneticl members operable into engagement under ,the influence of said Wind-- ings, said members' having engaging surfaces of such shape that the engaging surface of one member is 'enveloped within the engaging surface of the other member, and a pole shading winding located on one of said members so as to encircle the enveloped and ,enveloping engaging surfaces of said members.

`2. An alternating current electromagnet lcomprising magnetizing windings, relatively movable magnetic members operable into engagement under the influence of said windings, said members having complementary enveloping and enveloped engaging surfaces, and a pole shading winding mounted on the member having the enveloping engaging surface so as to encircle an enveloped portion of the other member. v 'y Y 3. An alternating current electromagnet comprising magnetizing windings, relatively y movable magnetic. members operable into ein` gagement under the influence of said wind- \ings, one of said members havin a concave engaging surface and the other o said members having a complementary convex engagf ing surface, and a pole shading winding mounted on said one member adjacent the concave engaging surface thereof. L

4. An alternating current electromagnet comprising magnetizing windings, a magnetic structure therefor including a frame and a relatively movable magnetic member operable into' engagement with the frame.

under the influence of said windings, said frame and magnetic member having complementary enveloping and enveloped engaging surfaces with the enveloping surface on the frame,'and a pole shading winding mounted on the frame in symmetrical alignment with rame adjacent said complementary lconcave surfaceso as to encircle a'portion of the convex end'of said plunger when the plunger Ais^in` engagement with the frame.

6. An ralternatingA current electromagnet comprising a laminated 'frame having an opening at one side anda concave surface formed opposite the opening, magnetizing windings mounted within the frame with the core space of the windings in alignment with the said opening and the said concave surface, a laminated plunger having a convex surface at the end thereof operable Within said core space into engagement with the Iconcave surface of the frame and havingv an enlarged head cooperating with the sides of the frame adjacent to said opening to form two substantially closed magnetic-flux paths in parallel relation, and a pole Shad ing winding mounted on the frame adjacent the said concave engaging surface thereof to encircle a portion ofl the .convex end of the plunger enveloped by the concave surface of the frame. f

7'. An electromagnet comprising magnetizing windings and 'a magnet-icvstructure therefor `,including a magnetic frame substantially encircling the windings and having an opening at one side and a polar projection extending within said windings opposite Asaid opening and a magnetic plunger adapted to operate through said opening into engagement with the said.V polar projection, the engaging ends of the plunger and the polar projection having complementary enveloping and enveloped surfaces,

and a pole shading winding symmetrically located with respect to said surfaces for insurinU magnetic and mechanical balance of the plunger in the attracted position.

8. An electromagiiet comp-rising magnetizingwindings, a movable magnetic plunger yeo having -a convex surface at the end thereof operable within said magnetizing windings and having lateral projections at the other end thereof, and a magnetic frame substantially encircling ,the coil and having a concave surface for engaging with the curved end of said plunger, said frame providin a' substantially closed multiple returnM` ux path through said lateral projections of the plunger when the said tracted position.l y

9. An electromagnet comprising a ma netic frame having an opening at one'side and a polar projection opposite the opening formed with a concave end surface, mag-.-

netizing windings inounted within the frame with the core spacefof the windings in align- `-inent with the said opening and the said concave surface of the polar rojection, and a' movablemagnetic member aving 'a body portion 4operable through .said aligned open- -ings in the frame and windings with one end presenting a convex surface complementary to the concave surface of the polar projection and the other end provided with lateral extensions overlappingthe frame on opposite sides of the said opening therein when the said complementary surfaces-of the inagplunger is in the atpolar projection plementa'ry cylindrical Aengaging surfaces for insuring magnetic and mechanical vbalance of the plunger in the attracted position, and the said plunger andthe opening in the frame 1having non-circular cross sectional shapes .for maintaining the said cylindrical engaging surfaces of the plunger and the frame in substantial alignment during operation of the plunger.

11. An alternating current electromagnet` comprising magnetizing windings, .relatively movable magnetic members operable into engagement under the influence of said windings, Aa pole shading winding mounted on one of'said members in symmetricalalignnient with the surface thereof engaged by the other member, one of said members having a slot formed therein intersecting the axis of said pole shading winding to maintain the members in magnetic equilibrium. l

12.- An electromagnet comprising magnetizing windings, relatively movable magnetic members operable into engagement under the'influence of said W'jindings, said members having complementary concave-convex engaging surfaces, and a-pole shading winding mounted on one of said members in symfmetrical alignment with the engagingsurface' thereof, said member having a slot formed therein intersectin and in symmetrical` alignment with t e axis of said pole shading winding for balancing the magnetic action thereof.

13. An electromagnet comprising inagnetl izing windings, a laminated magneticV structure therefor including a frame and arelativel movable member, and a pole shading Vwin ing formed Vof a pluralityof spaced apart rivets extending across the laminations of said structure and having their ends' welded to the' outer laminations thereof.

14. An electroma et comprising magnetizing windings, a l minated magnetic structure `including a movable magnetic core member operable within said magnetizing windings and a substantially rectan lar magnetic frame encircling'r said win ings and having an o ening in one end thereof for receiving sai core member, and a'pair f of angle supports for the electromagnet disposed -in opposing relation at the said one end of said frame and secured together for maintaining the frame laminations adjacentV said o ening in alignment, and a second .pair o angle supports for the electromagnet on any one of the said supports.

net secured together in opposin relation at frame having a core opening in one side the opposite end of saidframe, t ev outstandthereof, a magnetizing winding located withing leg of each ofsaid pairs of angle sup- 1n Said frame m'alignment with said openorts being provided with fastening means ing, a core member operable through s-.iid or permitting mounting of the electromagopening into said magnctif/.ing' winding, arms secured on said core member in spaced 15. An electromagnet comprising magnetrelation to straddle the side of the frame op.- izing windings, a magnetic frame substanposite said opening fory transmitting the optially encircling said windings and having erating forceof the core member, aipair of an opening in one side thereof, a magnetic/ members secured in opposing relation at the plunger operable through said opening into end of the frame having the' opening therein engagement with the opposite side ofthe and servingas guides to maintain said core frame, andarms secured on sai plunger'in member in said opening, a second pair olf s aced Vrelation to straddle the side of the members secured in opposing spaced relation ame lopposite the opening for transmitat the opposite endot the rame to provide ting ythe operating force of the plunger.-

16. An electromagnet com rising magnet-v cere member operate. izing windings, -a magnetic rame encircling '22.An electromagnct comprising a subsaid windings and having an' opening in stantially rectangular magnetic frame havone side thereof, a magnetic plunger opering a substantiallyl rectangular opening in able throughsaid opening into engagement fone side thereof, magnetizing windings Alowith the opposite side ot' the frame, arms cated within said frame in axial alignment f plunger.

18. In "an electromagnet, a magnetic end of the magnetic frame tol vNi e s lid-v secured on said plunger in spaced relation to with said opening, a plunger of rectangular straddle the opposite side ofthe frame, and cross section operable through said opening means at the outer ends of said arms` and into said magnetizing--Windin s, arms se Vsaid plunger for establishing connections for cured on opposite sides of sai plunger in 'transmitting the operating force of the spaced relation to straddle the side ot the frame opposite said opening, an two pairs 17. An electromagnet comprising magnetof angle supports for the electromagnet, one izing windinrs and v,a movable Ama rnetic pair secured in opposing spaced relation at member opeaible under the influenceioi5 windings, said member being laminated with opening therein and serving' as guides to the laminations formed to provide a slQt and prevent lateral displacement of said plungy guideways througlr'which said arms on thesaid4 the end of the magnetic frame havinwsaid a hole transversely intersectingy the slot at er, the other pair of angle supportsfbeing y one end ol the'magnetic member. secured in spaced relation with the o posite frame, a magnetizing Winding' therefor having guidewaysrfor said arms on the plungmg a winding spool provided with opposite end flanges formed 'with a slot in thefouter supports being provided with 'fastening comprisingl face of one end fiange anda correspondingI means for permitting mounting ofthe elecprojection on the outer face' of 'the' other tromagnet on any one orv morre'of said supend ian e, and means cooperating with said. ports.

slotv an saidV rejection for` securing thef windin s ool moperating position in the magnetic rame. xv Y 19. In an Lelectromagnet, a' magnetic stantially rectangular magnetic frame having a core opening 1n oneslde thereha magnetizmg winding therefor carried on a gtheoutstanding leg of each of said anglel 23. An electromagnet ycomprising a subframe, a magnetizing winding therefor a plurality of s ools each provided wit opposing end anges. for lsupporting the winding therebetweem said spools having means associated Withuthe. outerface of each end flange for interlpgk ing. the spools to ether in operating relation in the magnetic rame. f

20. An electromagnet comprising a magnetio frame, magnetizing windingscarried on a plurality of spools for mounting in spool provided with opposing end flanges of substantially rectangular shape with a slot formed in the outer face of one end` flange anda projection located on the oiiter face of the other end ylang'e"and means for securing said winding spool in operating 'alignment in said 'frame comprising locking members registering with said slot and said core opening and resilientspring members interlocking with the opposite end of the r'frame and said projection.

alignment within said frame, said spools-. 24. An electromagnet comprisinga subhaving mechanical interlocking" menans on their adjacent sides and on their outer sides, and resilient means 'cooperating /with said interlocking means for holding the windingy A spools in alignment within said frame.v

21.' An electromagnet comprising a substantially p rectangular laminated magnetic stantally rectangularlaminated magnetic trame having a core'openin of substantially rectangular shape'in. one si e thereofya mag- Niiange yand a, corresponding projection located on the outer face of the opposite end 5 flange Afor interlocking the adjacent end anges of the spools to ether with the spools end'to end, and means or secuiing the spools in said frame comprising locking members one portion of which is arranged to interlockthe slot in the oter end ange of 'one -of the spools with the core opening in said frame and another portion .of which is are ranged to interlock the lprojection on the outer end Hange of the ot er spool with the opposite end of the magnetic frame.

, In Witness' whereof Ivhave hereunto set my hand this 6th da ofMay, 1927.

PANE LO TROMBE'ITA.

@ERTHFCATE 0F CORRECTON.

Granted December '25, .1:

mimo to it is hereby certified that errer. appears in the primed specification oi the abovev numbered patent requiring correction as iol'iows: Page 7eiine 38;@ eieim "18, for the word "opposite" read "opposing"; end that the said Letters Patent shouid be reati with this correction therein that the same may @einem to the record of the case in the Patent iiiee.

Signed andv sealed this 5th djey oi February, D; ,11929.

een

ti, i. tiem,` p Acting Goissiomer oi Patente,