US2152042A - Power relay - Google Patents

Description

March 1939- 0.13. GRANDSTAFF 2,152,042

POWER RELAY Filed Feb. 6, 195'? 2 Sheets-Sheet 1 INVENI'ORZ FIG. 0THO. 0. GRAND'STAFF BY fig, 3

,ATTORNEYS.

March'28, 1939. O, GRAN'DsTAFF 2,152,042

POWER RELAY 2 Sheets-Sheet 2 Filed Feb. 6, 1937 85 33 I I 90 85d? 5 5 5 FIG; H

mm OTHO D. GRANDSTAFF V v ATTORNEYS.

Patented Mar. 1939 POWER RELAY.

OthoD. Grandstaff, Chicago, 111., aseignor to Associated Electric Laboratories, Inc., Chicago, Iil., a corporation of Delaware Application February 0, 1931, Serial rim 124,420

1 Claim. (01. zoo-s1) This invention relates to improvements in power relays intended primarily for use on alternating current circuits and adapted for the remote control of various line circuits and the like where it is desired to make and break circuits having currents of considerable magnitude passing therethrough.. The power relay of the present invention 'is of the magnetic type and l is capable of being operated by either direct or alternating current for the purpose of closing circuits, such as the circuits to battery'chargers and battery eliminators or the like, although it may have other uses.

The principal object of the invention is to provide an improved magnetic relay of simple,

compact construction which may be manufactured with ease and economy and which will be eiiiclent in use. A further object of the invention is to provide an improved relay comprising improved means for mounting the magnetizable core and thearmature which is actuated when the'core is energized. Another object is to provide a magnetic relay having a core and an armature in combination with means for rel lating the magnetic field which must be applied to the armature to actuate it. Still another object of the invention is to provide an improved power nelay having improved meansfor controlling the intensity and time relation of the magnetic fleld in different parts of the core for the purpose of permitting the device to he employed emciently in an alternating current circuit- A further object of the invention is to' provide an improved power relay having means for effecting an abruptshut-oif of the are which normally tends to continue when a circuit is broken. Other objects relate to various features of construction and arrangement which will appear more fullyhereinaiter. The nature of the invention will be understood from the following specification taken .with the accompanying drawings in which .two embodi ments of the invention are illustrated. Inthe drawings, Figure 1 shows a rear elevation of one form of power relay embodying the present invention; Fig. 2 shows a front elevation of the relay illustrated inFlg, l; ,7 Fig. 3 shows abottom plan view of the relay 5 illustrated in Figs. 1 and 2;

Fig. 4 shows a side elevation of the relay illustrated in Figs. 1 and 2, looking toward the left asvlewedinFig.1;

a Fig. 5 is a somewhat tic view. of the circuit connections of a power relay embodying the present invention, showing one useto which the relay may be put;

Fig. 6 is a perspective view of the magnetic core and magnetizing coil of the relay shown,

in Figs. 1 to 4, inclusive, with a portion of the 5 bracket by which the armature is supported on I the upper portion of the core broken away; I

Fig. '1 is a perspective view of the armature which is actuated by the core illustrated in Fig. 6; together with the spring contacts which are 10 operated by the movement of the armature: I

Fig. 8 shows a top plan view of the shaft and swing by which the movement of the armature is controlled;

Fig. 9 shows a side elevation of the lever arm l5 laminations of a shading coil employed 'in the pole face as shown in Fig. 6; and

Fig. 11 is a bottom plan view of a modiii form of the invention in which magnetic blowout coils are employed for preventing arcing of the contacts when the circuit is broken. y

Before proceeding toa description of the con- 25 struction of the improved power relay, reference will be made to the circuit connections of one possible use of the invention, as illustrated in Fig. 5; As there shown, two line conductors I5, leading from a source of alternating or direct current supply, are connected immovable con-' tact members it, each of which is adapted to engage either one of two stationary'contacts II and It. The contacts I! are connected by con ductors it to the terminals of a' load 21, and as the contacts ll areconnected. by conductors 22 to the terminals of another load 23. By changing the positions of the movable contact members I, either of the loads II or 23 maybe connected in the circuit of the line conductors ll. 40

This movement'of the contact members I. is effected by'a magnetizable armature 24 which is' adapted to be actuated by a magnetisable core ll. The winding of the core Ilia adapted to be energized by a current. supplied theretos throughoonductors 2t,'leading from the ree ondary winding of a transformer 21 which has j its. primary winding connectedthrough conductors II with a suitablealternating current supply. Aswitch-Ilisconnectedinoneottheeonducton so It which,- for example, may be associated with the line conductors of atelephone circuit, the switch 2! being located at'a point remote from 'thelocsticn'o'f'therelaywhmhcontrchthecontea-imam".

As shown in Figs. 1, 2, 3, 4, and 6, the magnetizable core of the relay is an E-shaped member, made up of superimposed iron laminations, secured together by rivets 25a, the core comprising parallel outer arms 25b and a central arm 25c upon which the magnetizing coil is positioned. These arms 25b and 250 have pole faces 26d and Ne, respectively, the central arm 250 being adapted to be engaged by the armature 24 when the coil 30 is energized. The anns 25!) are preferably slightly shorter than the arm lie so that the central arm is the only one actually engaged by the armature, there being small air gaps between the pole faces 25d and the armature, an arrangementwhich is adapted to prevent chattering when the relay is in use. The coil 80 is provided with an insulating covering 30a and is wound on an insulating spool having heads "b at its ends, the length of the coil being such that the central arm 250 of the core projects beyond the adjacent insulating head 30b of the spool, as shown particularly in Fig. 1. This pro- Jecting portion of the arm 25c of the core is provided with a pair of parallel slots ing inwardly from the pole face He thereof, as shown in Fig. 6, and these slots are occupied by portions of the shading coils 3i which are shown as being made up of superimposed laminations lla of copper or the like, thus forming continuous rings which surround the outer end portions of the central arm 28c of the core. These shading coils, due to curents induced therein by the magnetic flux, are adapted to produce magnetic fields opposed to those caused by the winding 80 in the outer 250 of the core, thus causing the resultant magnetic flux in the outer portions of the central arm to be out of phase with the magnetic flux passing through the portion of the pole face which lies between the two shading coils, with the result that a continuous magnetization is maintained in some portion of the pole face when the coil 80 is energized by alternating current, so that the armature 24 will be attracted to the core as long as the current continues to pass through the coil 30. The laminations lid of each shading coil may be secured together and the apertures lib of the shading coils are adapted to be fitted closely by the projecting portions of the magnetic core so that the shading coils are thereby held firmly in position.

The core 2! is connected with a parallel in- Iulating plate 83, of "Bakelite" or other suitable material, which is attached to the core at the lower end of the relay by an internally threaded sleeve 34, engaged at one end by a screw ll Pissing through the insulating plate and at the other end by the threaded extremity of one of a series of studs 8! which pass through the core. At the upper end of the core II, the side arms 25b are connected with the insulating plate II by a metal bracket 31, which has the form shown particularly in Figs. 4 and 6. This bracket comprises a top plate I'Ic having depending therefrom a pair of-iianges 31b which are secured to the insulating plate a by screws ll engaging threaded apertures therein. The depending flanges 31b of the bracket are formed in rally with parallel ransversely extending arms 31c, which have their extremities turned inwardly, as shown at lhL'to seat against the faces of the upper ends of the arms Ilb oi the cores These lnturned extremities IId are provided with threaded apertures which are engaged by the threaded portions of two of the studs ll previously referred to.

25 extend-- portions of the central arm which the armature is carried. The

The bracket 3! which thus connects the insulating plate 33 with the upper end of the core, also serves to support the armature 2- which, as shown in Figs. 4 and 7, is made up of a plurality of laminations 24a of magnetizable material having a metal plate 24b seated against the outer side thereof. A hinge bracket 40 seats against the inner edge of the stack of laminations 24a and this bracket is secured to the laminations and to the plate 24b by rivets 4|. of the hinge bracket, there is positioned an insulating block 42 upon which are seated the movable contact members ii which are in the form of flat leaf springs of bronze or the like, each carrying a pair of oppositely projecting contact lugs I So and I6?) at its lower extremity. The contact springs l8 diverge downwardly from each other and their upper ends are engaged on their outer sides by an insulating plate 43 on which is seated a metal plate 44. A pair of screws 45 extend through the plate 24b, through the laminations of the armature, through the bracket 40, through the insulating members 42 and 43, the upper ends of the spring contact arms l6 and through the plate 44 which has threaded apertures to receive the ends of the screws, as shown in Fig. 7, so that the upper ends of the contact springs II are mounted rigidly on the armature and are insulated therefrom.

The arms 40a of the bracket 48 extend on the inner sides of the arms 81c of the bracket 3! and are pivotally connected therewith by a shaft 41 which extends through aligning apertures in the ends of the arms 40a and in the adjacent portions of the arms 31c. This shaft 41 has wound thereon a coil spring 48, shown more particularly in Fig. 8, which has its middle part engaging apertures in the shaft and which has its opposite end portions wound in opposite directions in helical fashion about the shaft, the extremities of the spring terminating in arms 48a which are provided with transversely bent extremities 48b arranged to fit into apertures 40b, formed in the arms 40:: oi the bracket 40 by shaft 41 is normally held against rotation and the spring 48 tends normally to move the armature 24 to its open or retracted position, as shown in Fig. 4. The extent of this opening movement may be limited by the engagement of the upper side 'of the armature with the edge of the top plate 31a of the bracket II, but it may also be limited by the engagement of the contact lugs Ito with the stationary contacts as hereinafter more fully described. In order that the tension of the spring 48 may beadjusted to regulate, the force which must be applied to overcome the spring when the armature is attracted to its core, means are provided for turning the shaft 41 in its bearings. For this purpose, one end of the shaft isconnectedtoacrankarmflwhichisinthe formofaflatplateadaptedtoseatagainst one of the side arms 31c of the bracket 81. This crank arm 4| has an aperture 40a in one end thereof which is provided .with outwardly extending notches 40b, shown in Fig. 9, into which a portion of the metal of theshaft 41 enters when the end of the shaft is riveted over the face ofthe crankarm asshownin Fig. 8. This crank am my be used for turning the shaft 41 to create the. desired tension in the spring 4| and. when that has been accomplished, the arm 40 may be secured in adjusted screw II which engages an aperture in the outer end of the arm and a threaded aperture in the Between the arms 40a parts of the armature moves from adjacent arm 310 of the supporting bracket. By this method of construction the armature 24 is caused to'move about a pivotal axis which excaused to beexerted on the armature by the several pole faces.

The large cylindrical heads 33a of the studsv 39 are adapted to seat against an upright support or panel 5| of an instrument board or the like, and the relay is adapted to be secured to this panel by screws 52 which pass through the panel and engage the internally threaded sockets 39b of the heads 36a, the screws being inserted thus mounted on the in 'plate 33 to from the rear side of the panel. The heads 38aof the studs are provided with transverse slots 360 for engagement with a screw driver or the like during the operation'of securing the insulatthe core of the relay. Although the relay may be mounted in various positions, it may preferably be located in an upright position such as that shown in Fig. 4, with the springs l6 extending substantially in 'a vertical plane so that dust will not collect materially on the operating surfaces of the contacts. when 7 panel 5|, theinsulating plate 33 is at the'front of the assembly in a convenient position for connecting to the contacts carried there by the various conductors of the circuit inwhieh the relay is used, such as the conductors which have-been shown by way of example in Fig. 5.

; pair are secured together by screws 51 and also is provided For the purpose of connecting the conductors 26 to the terminals of the coil 39 by which the magnetizable core at its upper end with a pair of metallic contact plates 54 and these are opposed on the inner side of the plate by metal terminal plates 55 to which the conductors 56 leading from the terminals of the coil 30 are soldered or otherwise secured. The plates 54 and I! of each by contact screws 58 by which the ends of the conductors 25 may be clamped against the faces of r the plate 54 to complete the electrical connections.

The line conductors llshown in Fig. 5 are adapted to be connected to contact plates 39 which are located on the face of the insulating plate 33 opposite other metal plates 3| which are located on the inner surface of the insulating plate. These terminal plates ii are soldered or otherwise secured to conductors 92 which have their other ends soldered or otherwise at.- tached to the contact springs l3, adjacent the free ends thereof. The plates 99 and 3| of each' pair are secured together and .to the plate 33 by screws 93 and also by contacf screws 34 which are adapted to receive beneath their heads the,

extremities of the conductors ll. The contacts l3,shown in Fig. 5, are riveted or otherwise secured to the free ends of metal brackets 33 which have the-angular form shown particularly in Fig. 3, each bracket having a portion Ila seated against the inner face of'the plate 3 3 and connected by anoutwardly inclined portion 9th with an extremity 95c which lies parallel .to the portion a and to which the contact i9 is riveted or otherwise secured.

contact plate 33 is located on the outer face 6} proportions of the parts, substantially equal forces of attraction may be is energized, the plate 33 may be used with the magnetizing coil 3 a opposite the portion at plates 99 are sethe insulating plate of .each bracket 83 and these shown in Fig. 5' are carried by brackets 19 which have their inner ends 19a seated against the inner face of the plate, 33 and which have inclined portions 10b connecting the portion Ila with the extremities 10c upon which the concured to the portion 95 and to the plate 33by a contact screw 69 which tacts I9 are mounted in positions offset from the plate 33 and from the portions 65a of the bracket 65. Contact plates II are seated on the outer face of the plate 33 opposite the inner portions 19a of the brackets 19 and these parts are secured together and to the insulating plate 33 by screws 12 and also by contact screws 13, which clamp the ends of the conductors 22 in position, thus connecting the contacts IS with the load 23, as shown in Fig. 5. By this method of construction, the terminal screws by which all of the conductors are connected to the relay are readily accessible on the front facepf the insulating plate 33 while all of the movable parts of the device are concealed behin this plate. v, When the relay as thus constructed is connected in the circuit in the manner illustrated in Fig. 5, the closing of the switch 29 will energize the electromagnet so that the core 25 will attract the armature from the position shown in Fig. 4, thereby causing the movable contact springsv It to be swung to a position wherein the {contact lugs IGb carried by their extremities will engage the 'pontacts i9 and thus connect the line conductors IS with the load 23. While the winding 30 of the core 23 is thus energized, the shading coils 3| will cause a lag of the magnetic field in certain parts of the pole face of the core behind the field in another part so that there-will be a continuous attraction of the armature 24 over some part of its area during the entire time that the coil 39 is energized. When the switch 29 is opened, the spring 49 will at once cause the armature 24 to rise to the position shown in Fig. 4, and during this movement the contact lugs lIa carried by the contact springs I will move into engagement with the contacts l8, thus connecting the conductors ll with the load 2|. The mounting of the contact springs i9 is such that as its contact lugs engage or disengage either set of contacts II or l9, there will be a wiping contact of the surfaces of the metalso that a good electrical connection isestablished each time that a contact is made. Although the extreme upper movement of the armature 24 is limited by the top plate 31a of the bracket 31, the engagement with the part 31a does not occur until after the desired contact has been established between the members "a and I2. v

If desired, the relay of the present invention 39 concircuit, in which case nected in a direct current the shading coils 3| may be eliminated. It is desirable when using the relay to break circuits in which comparatively large circuits are passing. and particularly when the relay is being employed with the line conductors II connected in a. direct current circuit, to provide means for ex- 24 and draw it downwardly current through the ously described,

tinguishing the are which tends to form between the movable contacts and stationary contacts each time the circuit is broken, and for this purpose the relay may be modified as shown in Fig. 11 to include permanent magnets in conjunction with the brackets which carry one set of stationary contacts, so that a magnetic ileld is maintained, which tends to oppose the passage of a gap between separated contacts, thus causing the flow of current to be shut oii' abruptly when the contacts are separated. In this arrangement, as shown in Fig. 11, the magnetisable core ll corresponds to the core 2! or the construction previously described, and the in sulating plate 83 corresponds to the plate 33 of the first form 01' the invention. All parts of the two relays are otherwise identical in construction except that the brackets 85 oi non-magnetic material, corresponding to the brackets i5 previhave the contact-carrying portions lle connected by right angularly extending portions lib with the parts "a which lie in coninner face of the insulating plate thus mounted closely adjacent the gaps between two stationary contacts and the cooperating movable contact, so that a magnetic field is set up which extends across these gaps or through the region between the contacts in which the tendency i'or arcing may arise when the contacts are separated. The coating oi. varnish on the maging associated ing panel and said between opposed contacts so that the arc is abruptly extinguished.

Although two forms or the invention have been shown and described by way of illustration, it will be understood that it may be constructed in various other embodiments coming within the scope or the appended claim.

I claim: I

A relay construction comprising a core, an insulating panel arranged on one side of said core, means including a plurality of supporting members attached to said insulating panel and engaging said core for retaining said insulating panel in spaced relationship with respect to said core, means including a plurality of studs extending through openings provided in said core and in threaded engagement with said supporting members for securing said insulating panel to said core, a supporting panel arranged on the opposite side of said core, means including additional studs extending through openings provided in said supporting panel and in threaded engagement with said first-mentioned studs ior supporting said core and the parts carried thereby upon said supporting panel, a movable armature carried by said core, means including a windwith said core for controlling the position oi said armature with respect to said core, a stationary contact carried by said insulating panel and arranged between said insulatcore, a movable contact arranged between said insulating panel and said core and associated with said stationary contact, means including said armature for controlling the position 01' said movable contact with respect to said stationary contact, and terminals for said winding and said contacts carried by said insulating panel.

' OTHO D. GRANDSTAFF.

Images