US2536162A - Relay - Google Patents

Description

Jan. 2, 1951 O s, FIELD 2,536,162

RELAY Original Filed Oct. 14, 1940 FIG. 3

156 941;; FIG.4 m-

T I FIG. 5

1m .1 Bu Mum,

15(0 93.92.9313! 157 w attorneg Patented Jan. 2, 1951 RELAY --=Oscar S; Field, Rochester, N. Y.,' assignor to Genaeral-Railway- Signal Company, Rochester, N. Y.

*Applictmtion'April 17, 1945, Serial No. 588,748, now 'Patent'No. 219L098, dated December 13, 1949, iwliich is a division of application Serial No. 361,060, O'ctob'er -14, 1940,"!w Patent No. 2,376,534; dated'May 22, 1945. Divided and this =-.application-0ctober 25, 194-7; Serial No. 782,211

"3 Claims. 1

"This invention relates to electromagnetic relays for use on railways, ,andmoreparticularly pertains to relays of the'polar-biased type for dis- "tinctive response 'topolarized' control circuits.

This application is a clivision of my .copen'ding application SerialNo. 588Q'748ffil'ed April 17,1945, now Patent No."2,49l,'098, dated December 13, 194.9, which is a 'division'ofselial No."36l',060,filed October14,-1940, which has resulted in a patent, Nof 2376,534, dated May 22,1945, in" which the relay" structure" or the "present invention besides operating "relay contacts also acted to operate themovable'spectacle of a searchlight typesignal; and no claim is -interic'le'd to'be "made inthis application to 'subjectmatter claimed-in such '00- pending application-andpatent.

"Oneof the objectsof thefpr'esent invention is to; provide polarized and neutral electromagnets soassociated' with each" other in a unitary structure and circuitorg'anization that the armature of the neutral "electromagnet will respond to either polarity" and will'lremain picked up upon a relatively 'qui'ck"reversal of polarity; while the armature of"the. polarized electromagnet' will be actuated only in'response" to energization' by said particular "polarity.

"Other objectaipurposes andcharaeteristic features ofthejpresent invention will be'in part obvious from theaccompanying"drawings. and in part pointed outas' the descriptiono'f the invenb tio'nprogresses.

jln'describing the invention-indetail; reference will be'ma'de" to" the accompanying drawings, in which like reference characters designate corresponding 'parts throughout the several views; and in which:

Fig. '1 I illustratesin a diagrammatic "and conventional mannerthe circuit 'organizationrelating' the electromagnetic structure of the present invention'ito an external control circuit;

Fig."2is' a front elevationof a relaystructure embodying the presentinvention;

"Fig. 3" is a"sideviewfof"the'relay"structure with parts shown in sectionas takenon line 3-3 of Fi ."2';

Fig. "'4 is a *top' viewdf "therelay'structure embodying thepresentinverition and shownin Fig. 2';'"and Fig.5 isa'sectiona'lview of the'jpolarized electromagnetto show the -shapeof the "molded permanent magnet.

The relay structure of the "present "invention comprises'a "frame member 'I 5 which is' preferably molded'of some suitable-. nomma'gnetic material, such as brass, aluminum. Bakelite "or the like.

'2 This frame structure has a shelf extending across the-back portion and protruding outwardly from its back portion (as seen in Figs. 2 and'3) upon which the neutral and polarized electromagnetic relays NR and PR are mounted.

Referring to Fig. 2, it will be noted that each relay'structure comprises a core and winding structure, an associated tractive type armature, and a contact group. For convenience, the armatureof the neutral relay has been designated Y; while'the armature of the polarized'relay has been designated G. Each armature operates its group of contacts through suitable pusher members l2!l, as will presentlybe described ingreater detail. The polarized relay PR also includes a permanent magnet [55 as can best be seen in Fig.4.

As can be most clearly seen in Fig. 4, the shelf portion 15 carries the two electromagnets or relayshaving coils es and 9|, and these relays are placed side by side and extending from rear to front'of the shelf '15. Since these two relays are similar so far as their coil, armature and contact structure is concerned, only one of them willbe described in detail, and this description will be more particularlydirected to the polarized'relay which'includes the permanent magnet I55. Referring to Fig. 3 which is a sectional view of the polarized relay PR taken 'on line 3-3 of Fig. 2, it can be seen that a core 92 carries the winding or coil 9!; is positioned above the shelf 15; and is connected in a magnetic circuit ineluding downwardly extending legs 93 and 94, carrying pole pieces 95 and 96, with an air gap between their inner ends.

The armature G, as viewed in Fig. 3, is pivoted at its rear end by a suitable needle bearing such as disclosed in my copending application Serial No. 548,354, filed August 7, 1944, now Patent No. 2,435,000, granted January 27, 1948, to which reference may be made for the details of such'a bearing. It is suiiicient for the purposes of the present disclosure to know that a flattened surface provided by a bearing plate I05 is held in position by two depending legs upon which are mounted springs I I9, so that a needle bearing H 8, which is received in a V-shaped slot in the top face of the armature, is held in position betweenthe armature and the bearing plate I05. In other words, the armature G is pivoted on a spring biased "adjustable needle hearing as disclosed in the'above mentioned application.

At theother end, the armature G normally rests against the adjustable back stop 99 mounted upon a suitably extending arm 10D. As shown,

the armature G is biased by gravity to its deenergized position. But in the parent application, now Patent No. 2,376,534, above referred to, a biasing spring was also disclosed for each armature to assure the restoration of that armature to its deenergized position by compensating for the weight of the spectacle arm which was jointly operated by the armatures G and Y through the extending arms I33 and I25 respectively. Since the spectacle operation has not been shown, the extending arms I33 and I25 have been omitted. The additional spring biasing means has also been omitted since they are unnecessary for the disclosure of this application. However, it is to be understood that spring biasing means may or may not be employed as may be most desirable for the operating values of the relay armatures.

As above mentioned, each of the armatures G and Y has associated therewith a group or bank of contacts. Each group of contacts comprises a plurality of movable contact arms I23 which may be operated between back contact arms I22 and front contact arms I2I by suitable pusher arms I20. The pusher arms I20 are pivotally connected to their respective armatures by slotted boss members I I6 with a suitable pivoting pin I II which is anchored against endwise movement by a spring latch II8 carried at one end by the lug H6 and at its other end springing into a notch I I9 in pin I I I. Since the movable contact springs I23 are normally held against their respective back contacts by the weight of the associated armature, there is a certain spring pressure provided by the back contact springs I 22 which the weight of the armature normally opposes, but the weight of the armature is assumed to be suificient to overcome this back spring pressure with plenty of margin. The fixed contact springs I2! and I22 together with the movable contact springs I23with their respective adjusting arms are mounted or molded into a suitable contact block I 40 as viewed in Fig. 3, each contact of course having a suitable extension to the right of the block I40 to provide for the connection of wire leads. These contacts mounted on the blocks I40 can be suitably adjusted before they are inserted into the relay mechanism. When the block I40 is mounted into its recess in the frame structure I5, a suitable mounting screw I4I at the top and a mounting screw I42 at the bottom are inserted so as to provide an adjustment of the proper location of the contacts with respect to the associated armature to give the desired contact pressure. The screw I4I can be left slightly loose and the proper adjustment of the contacts can be made with respect to the armature by turning the screw I42 to a proper position, the contact block I40 beingbiased outwardly against the screw I42 from the frame I by reason of spring I43. When the proper adjustment has been made, the screw MI is tightened and a lock nut I44 is set in position. Referring to Fig. 2, it is seen that a plurality of these contact blocks and associated ontacts are associated with each of the armatures, and each block is provided with its adjusting screws. With this arrangement of contacts, a variable number of contacts can be associated with each aramature without altering the design and, proportions of the structure as a whole.

, As above mentioned, the general magnetic structure of each relay PR and NR. is the same, but the polarized relay core structure includes soft iron extensions I35 and I36, one at each end of the core 92, which extensions are held in position against the respective legs 93 and 94 of 4 I the magnetic structure by the bolts I56 which hold the core 92 in position. Parallel with the core 92 and extending between the two soft iron extensions is a permanent magnet I held in position by suitable bolts I5? and this permanent magnet is shaped to fit around the coil 9I so as to conserve space and yet have the desired residual magnetic force.

In accordance with the present invention the permanent magnet I55 is provided with such cross sectional area relative to the cross sectional area of the core member 92 that its degree of residual magnetism effectively saturates the core member 92 with flux without producing an substantial degree of flux in the associated armature G. In other words, the close and intimate magnetic connection between the permanent magnet I55 through the extensions I35 and I36 to the core member 92 provides a magnetic path of such low reluctance that there is only a relative small leakage flux passing through the magnetic circuit including the armature G and the air gap between it and the pole pieces 95 and 99.

Fig. 5 shows a cross-sectional view or the core member 92 and the associated permanent magnet I55. From this it will be seen that the permanent magnet I55 is clamped into position by bolts received in the molded recesses of the magnet. In this connection, it may be noted that modern manufacturing of permanent magnets is effected by a molding or sintering process for economical production, and the structure of the present invention takes advantage of this fact.

Referring to the diagrammatic illustration of Fig. 1, it will be seen that the neutral relay NR is associated with the polarized relay PR through a rectifier unit I54 by suitable circuits includin a manually operable push button I53 and connected to terminals which may be energized with current of either polarity as indicated by the symbols and Both the armatures Y and G are shown as being connected t their respective movable contacts I23. The polarized relay PR has been illustrated as having its permanent ma net I55 mounted above the core 92 for convenience although it is actually at the side as shown in Fig. 2. This permanent magnet is magnetically connected in multiple with the core 92, and it has sufficient residual magnetism to substantially saturate the associated core 92.

When the switch or push button I53 is actuated to close the control circuit, and assuming minal while negative potential is placed on the upper terminal, then current flows through the left-hand portion of winding 9| on core 92, through the rectifier structure I 54, winding on the neutral relay NR, through the rectifier I54, through the right-hand portion of the winding 9| on core 92, to the other terminal. The current which thus flows in the winding 90 of the neutral relay acts to produce magnetic flux in its core structure which is efiective to actuate its armature Y to a picked up position.

The magnetic flux produced in the winding I on core 92 with this polarity applied to the circuit organization acts to produce a magnetic flux which is in the same direction as the flux of the permanent magnet I55 passing through the core 92, as indicated by the dotted arrows within the core 92 and the solid arrow in the permanent magnet I55. Since the residual magnetism .of the permanent magnet I55 substantially saturates the core member 92, the energization of the winding 9i to the'usual degree required for the operation of the neutral relay-NR is ineffective 111to :produce any-substantial I change in the mag- :ineticflux'of the core structure. This-will be bet- ;ter'appreciatedbyrealizingthat when a piece of :soitiron is substantiallysaturated, the-further cnergization of an associated winding produces only that additional flux which would'be producedif 'there were' no iron core. *This additional *ilux produced by such energization of the winding 9| has two possible magnetic paths, one through the permanent magnet |55,- and the other through *the armature G- and the associated air gap. Regardless of the ratio of division --o'f"this additionarflux through its two possible -paths, it does not actuate the armature G be- "cause itis of insuificient value and also because "that portion which-may pass through "the armature is in-oppositionto that leakagefiux which is 1 supplied by the'permanent magnet. Thus, it will he apparent that under these conditions the arzmature G is not actuated; while the armature Y immediately" assumes its actuated position. For i' these reasons, it can'be'seen that to energize the winding 9'! :sufiicientlywithlsuch reverse poarity astocausetheactuationof the armature would require manytimes the normal degree of enerwgization for the relaysPR and NR.

Ont-the other hand, if: the opposite polarity is ,applied to the: term nals of the circuit organizartionxofiFig, 1, it will be: apparent that the direcitiOll of magneticfiux in the core 22 will be retversedcas indicated .:by'the'associated solid line '"fiI IOWSFWhiIS the direction ofthe magnetic flux produced in the :neutral relay structure rema ns rthe'sameiby reason of the rectifier unit lbs. This opposite-polarity will of course cause the actuanztion of'the armature Y of the neutral relay, Also, 'the'magnetic flux producedinthe core 92 ofthe epolarized :relayfPR is 'now in opposition to the :ppermanent-magnet l55;rand'the cores! instead :of'furnishing arshuntpath'for the residual magnetism of the permanent magnet, opposes the flow. ofsuch residual magnetism so that there is a considerable increase of magnetic flux passing through the a-irgaoand the armature. This ,causes thecarmature G to beactuated or picked up thus operating its associated contacts. to open the back contacts and close the front contacts.

Thus, when the electro-magnetism is in the direction of the full arrow,. the core shunt onixthe permanent magnet is choked out, and the armaturepicks up, but when the electro-magnetism his Lin-the reverse direction it has no efiectito speak of, since the permanentrmagnet has saturated the coreand the armature remains 'reitracted.

From this it canbeseenthatthe application of energy of one polarity on the circuit organization causes both armatures'Yand G to respond; while'theapp1ication of energy of the opposite polarity results in the response of only the armature Y. If the reversal in polarity on the terminals of this circuit organization is relatively quick, it will be apparent that the armature Y will remain picked up. This is because the rectifier unit I 54 causes the winding 98 to always be energized by current flowing in the same direction regardless of the polarity of the potential applied to the terminals of the circuit organization, and a so because the rectifier unit I54 shunts the current induced in winding B l during a change in flux conditions so as to actually delay the decay of flux passing through its core and associated armature. Thus, if the reversal of polarity on the terminals of the circuit organization is relatively quick, the magnetic "flux'through the armature is maintained above that-valuenecessary to hold the armature picked up during such reversal. 5 The rectifier unit [54 is connected, as described I above, between the windings of the polarized relay PR and the neutral relay NR in a manner to have a portion of winding 9! between therecti- -fier and the terminals 'for protection against lightning or other transient'surges of potential which may occur across the terminals of the circuit organization.

From the above description, it will be observed that the permanent magnet l55an'd the .core' 92 -are magnetically in parallel through a closed magnetic circuit; whereas this parallel magnetic structure has extending pole pieces 95 and 95 'with an intervening air gap between them-and the armature G. Thus, the magnetic circuit involving the armature is of higher magnetic-reluctance than the other two "magnetic paths. For this reason, thepermanent magnet residual Hrnagnetism has practically no efiect normally on the armature G because such residual magnetism --issh=.rntedby the core 92. Similarly, shouldthe permanent magnet lose its residual magnetism ,due to a stroke oflightning, severe .vibration,:or thelke, it'in turn would provide. a shunt path nagnetism produced by the energizationzof the coil 53! and the armature would 'not;respond under a normal degree of energization of such winding.

In the draw s. illustrates a circuit or- Jh reit is assumed that ordinaril a ruler; potential will be; applied to the enerircuit such as will in one case operate ay armatures andin the other case op- However, itinay happen dueto re voltages, li htning surges and the like, that the potential applied to the energizing circuit will be several times normal degree of energizationrequired for operationoithere- In the event that such an abnormal energizing potential is of the wrong polarity for the r ,1 operation of the polarized relay, such potential still will not cause the response ofthe armature G. This is for the'reason above pointed t, namely, that the lines of flux induced by the gization of the winding iii in such a direction are in the same dir ction as the saturating mag- -ux norn the permanent magnet, and-um der :si. 1": circur tances the winding can merely is ac lines of r iii the same if the iron core :were not present.

A unitary relay structure has thus been shown .and described as comprisinga unit which isparticularly adaptable for use in polarized circuits, :having one group of contacts which --are controlled a 'al relay so as to respond to our- "sent of or rarity, having another-group of contacts controlled by apolarized relay .so as to respond to current of only a particular polarity. Such a unitary structure is particularly useful in control circuits for use along railroads and the like where reliable relays are required, and where protection against lightning surges and the like is necessary. Especially the provision of the polarized relay of the unitary structure which assures proper polar response even in case of wide variations in the degree of energization, is highly desirable for afety circuits where proper response to polar y is required.

In this connection, it should be understood that he principle of such a polarized relay may be employed in various types of relay structures and electromagnetic devices; and that the polarized relay structure PR may be used as a separate and individual device if desired.

Having thus described a relay structure and organization as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the invention rather than to limit the number of forms which it may assume; and it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, Without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:

1. In a structure of type described; two electromagnets each having a magnetic core structure including a back yoke and a cooperating armature associated with said core member but normally biased away from an attracted position; a permanent magnet intimately connected in multiple with the back yoke of one of said electromagnets; a rectifier unit; a polar energizing circuit having a direct current of either polarity applied thereto; two windings on the back yoke of said one electromagnet; a single winding on the back yoke of the other electromagnet; circuit means connecting the opposite terminals of said two windings of said one electromagnet to said polar energizing circuit with the other terminals of said two windings connected to said rectifier; and other circuit means connecting the out-put terminals of said rectifier to the opposite terminals of said single winding on said other electromagnet; whereby the energization of said energizing circuit with one polarity causes the armatures of both electromagnets to be actuated whereas the energization of said energizing circuit with the opposite polarity causes the actuation of the armature of said other electromagnet but not said one electromagnet; and whereby said rectifier is protected by said two windings of said one electromagnet from surges of static potentials.

2. In a unitar electro-responsive device, two electromagnets mounted on the same base plate each including an energizing winding on its core structure above the base plate and an armature pivoted with respect to the core structure below the base plate so as to be biased downwardly by gravity, a permanent magnet located between the two electromagnets and intimately connected in multiple with the back yoke of the core structure of only one electromagnet, a bridge connected rectifier unit located above the base plate and having in-put and out-put terminals, and circiut means connecting a winding of th electromagnet polarized by said permanent magnet in series with the input terminals of said bridge connected rectifier and also connecting the winding of said other electromagnet to the output terminals of said bridge connected rectifier, and contacts associated with each electromagnet and operated by its respective armature, whereby the contacts of both electromagnets are operated when said circuit is energized with current of one polarity but only the contacts of said other electromagnet are operated when said circuit is energized with the opposite polarity.

3. In a relay organization adapted for use in polarized direct current circuits; two separate electromagnets each having a U-shaped magnetic core structure, a winding on the back yoke portion of said core structure, and a cooperating pivoted tractive type armature adjacent the extending legs of said core structure and normally biased away from its attracted position; a permanent magnet intimately connected in multiple with the back yoke portion of said core structure of one of said electromagnets and efiectively saturating with magnetic flux that back yoke portion to thereby render that electromagnet capable of actuating its armature only when its Winding is energized with one particular polarity; a full-wave rectifier unit having input and output terminals; a control circuit at times having a direct current of one polarity applied and at other times having the opposite polarity applied; circuit means connecting the winding of said one electromagnet to said control circuit through the input terminals of said rectifier unit and also connecting the winding of said other electromagnet to the output terminals of said rectifier unit; whereby the energization of said control circuit with direct current energy of said one polarity results in the actuation of the armatures for both of said electromagnets, while the energization of said control circuit with direct current energy of the opposite polarity results in the actuation of only the armature of said other electromagnet.

OSCAR S. FIELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,554,318 Wright Sept. 22, 1925 2,008,511 McNairy July 16, 1935 2,141,803 Thompson Dec. 27, 1938 2,320,748 Pilasterer June 1, 1943 2,435,001 Field Jan. 2'7, 1948 2,491,098 Field Dec. 13,1949

FOREIGN PATENTS Number Country Date 257,924 Germany Oct. 26, 1912

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