US2515258A - Electromagnet with split core armature - Google Patents

Description

July 18, 1950 J. F. o'BRlEN Erm. 27,515,258

ELECTROIIAGNET WITH SPLIT CORE ARHATURE Filed April 8, 1947 2 Sheets-Sheet 1 H51 FIG. a /la A! /5 /ac /0 INVENTOR JOSEPH F. O'BRIEN BY JOHN BOAT DO ORNEY July 1.8, 1950 J. F. oBRlEN Erm. 2,515,258

ELECTROMAGNET WITHv SPLIT CORE ARMATURE Filed April 8, 1947 2 Sheets-Shea?I 2 lNVENTOR JOSEPH F. O'BRIEN Y JOHN B. ATA LDO Patented July 18, 1,950

ELECTROMAGN ET ARMA Lebanon, and John B. Cataldo, J., assignors to J ohn-B. Pierce Joseph F. OBrien, Annandale, N.

WITH SPLIT CORE TURE Foundation, New York, N. Y., a corporation o! New York Application April B, 1947, Serial No. 74.0,144

6 Claims.

This invention relates to electrical relays and to solenoid mechanisms component thereto. It constitutes an improvement on the subject matter disclosed and claimed in our similarly entitled copending application Serial No. 726,362 iiled February 4, 1947.

In that prior invention the relay and component solenoid 'mechanisms possess a single solenoid coil necessitating only a two-wire control circuit, as distinguished from earlier devices of similar type utilizing a pair of solenoid coils and a three-wire control circuit. Associated with the solenoid coil, as an armature, is a plunger assembly embodying a plunger or throw rod which eiects the end result desired of the device. The action of the components of the plunger assembly under successive momentary energizations of the solenoid coil, together with the correlative action of mechanical latching means operative on the plunger assembly, makes it possible to achieve a throwing of the plunger rod and a holding of it in its thrown position, as in the closing and the maintaining closed of a load circuit controlled by the relay, followed by a return thereof and a holding of it in its return position, and likewise for repeated operative cycles. Thus, such an electrical relay can be effectively operated remotely by means of a single momentarily acting push-button in the control circuit.

'I'he present invention retains the generic combination of single solenoid coil. plunger assembly,

` and mechanical latching system, but eliminates certain disadvantages inherent in the prior arrangement. f

Whereas in the prior arrangement resilient catches or latching elements are employed to effect mechanical latching of certain of the plunger elements component to the plunger assembly. and these require close tolerances in the manufacture of various of the parts, as well as frequent adjustment vduring use, 'in accordance with the present invention a system of rigid latches and levers, subject to neither of these disadvantages, is utilized to achieve the same end result.

Thus, itis an object of the present invention to eliminate both the need for close tolerances in the manufacture oi' a device of the type concerned and the need for frequent adjustments during its use. V

It is an object to reduce the cost of manufacture and upkeep.

It is a further object to provide for more positive operation and greater reliability.

These and additional objects and features of the invention will be fully considered in the following detailed description of the preferred specinc embodiment illustrated, by way of example only, in the accompanying drawings.

In the drawings:

Fig. 1 is a vertical sectional on the line I-I, Fig. 2, but for the most part centrally through the device in its unenergized om or circuit opening, position;

Fig. 2 is a horizontal section taken on the line 2 2, Fig. 1;

Fig. 3 is a horizontal section taken on the line 3' 3| Fg- Fig. 4 is a view corresponding to that of Fig. l, but illustrating the device in its energized on, or circuit closing, position;

Fig. 5 is a section taken on the line 5-5, Fig. 4;

Fig. 6 is a view corresponding to those of Figs. 1 and 4, but illustrating the device in its unenergized on position;

Fig. 7 is a corresponding view,

but illustrating the device in its energized oli position;

Fig. 8 is a fragmentary perspective view oi a portion of the latch mechanism drawn to an enlarged scale, the position of the mechanism corresponding to that of the upper part o! Fig. 6;

Fig. 9 is a similar view, the position corresponding to those oi' theupper parts of Figs. 4 and 7 and Fig. 10 is another similar view, the position corresponding to that of the upper part of Fig. 1.

Referring to the drawings: In the form illustrated, which is now considered to be the preferred form, the device comprises an external casing -III of cupped formation provided with an inset cover II removably secured in place by the screws I2. Both casing and cover are preferably formed of a non-magneticA material such as almninum. The cover is formed with an open neck portion Illa, into which is set a removableterminal block I3 ot insulation, such block' carrying electrical binding post arrangements I4 and I5. A set screw I6 serves to secure terminal block I3 in place.

Within the casing I0 is disposed the solenoidoperated mechanism of the invention, which, in this instance, serves to make and break an electrical circuit, and therefore is operable as an electrical relay. Such mechanism includes a single solenoid coil I1 enclosed by a shell of magnetic material, advantageously steel. the shell comprising opposite pole pieces I8 and I9 of disc formation, and a coil encircling ring 20. A spacer ring 2 I, which is deslrably of electrical insulating fiber, serves to retain the solenoid coil and its enclosing shell snugly against the internal view taken partially 3 shoulder formed bythe cover member . Electrical lead wires 22 and 23 extend from the respectivebindingpost arrangements I4 and |5 to the coil l1, and serve to conduct electricity thereto from a suitable control circuit (not shown), usually of low voltage-say 24 volts, which may be connected to the device by means of the binding screws |4a and |5a. Wiring leads 24 and 25 for connection with the electrical load circuit to be controlled by the device, a circuit which may be of considerably higher voltage than the control circuit, say the usual 110 volts of an ordinary domestic wiring system, pass through suitably provided openings in the casing i8 to electrical union with respective contacts 28, 26 which are secured in mutually spaced relationship to an insulating mount 28. .The interior of the casing below the mount 28 is preferably lined with insulation 29.

As in my afore-referred-to copending application Serial No. 726,362, the solenoid-operated mechanism includes, besides the single actuating coil, a plunger assembly which acts as an amature in the sense that certain of its components are movable by the magnetic ux of the coil; such mechanism includes, also, mechanical latching means operable on certain components of the plunger assembly, and a. snap spring oper- :ale on other components of the plunger assem- The plunger assembly comprises a plunger throw-rod 38 of brass or other non-magnetic material to which is xed intermediate its length, a solenoid-responsive plungerv element 3|. The rod 30 is capped at one end by a striker element 32, here shown in the shape of a disc, and is formed at the other end as an elongated shank 38a on which are positioned an opposite or second striker element 33, a snap spring in the form of a double equilibrium spring disc 34, and an electrical contact 35 sandwiched between blocks of insulation 38 and 31. A conventional nut and washer serve to secure the several parts tightly in place on the throw rod shank, as shown The spring disc 34 is anchored about its circumference in a frame structure 38 disposed between the mount 28 and the spacer ring 2|.

As so constituted the throw-rod extends through a suitably provided aperture inv the mount 28, so that electrical contact 35 is positioned to bridge the gap between the spaced contacts 28, 26 of the load Vcircuit when the rod is thrown by a given energization ofthe coil I1 acting on the intermediate plunger element 3|, seeFis. 4.

The plunger assembly comprises, further, a

pair of solenoid-responsive auxiliary plunger elements 48 and 4| freely mounted on the throwrod 30 at opposite ends of the fixed intermediate plunger element 3|.

Secured to the opposite pole pieces I8 and I9 are respective bracket plates 42 and 43. These serve to mount the latching mechanism about to be described. A coil spring 44 of brass spring wire or other suitable v non-magnetic material is 'interposed between the two auxiliary plunger elements, and normally urges both outwardly against the respective plates as limit stops, see Pigs. 1 and 6. T-he spring disc 34, it should be noted, determines the position of intermediate plunger element 3| relative to the auxlliary plunger elements, depending upon which position of equilibrium it is in, and energization of the'solenoid coil l1 determines the particular position of equilibrium oi the spring disc.

The latching mechanism is arranged to be actuated by the oppositely positioned striker elements 32 and 33, and to act upon the auxiliary plunger elements by means of4 respective` latch arms which engage flanges 40a and 4 la of the respective auxiliary plunger elements. .Such latching mechanism comprises two independent and oppositely disposed identical latch assemblies mounted on the bracket plates 42 and- 43, respectively.

Each latch assembly comprises a bell crank 50 pivoted on a horizontal axis (considered from the standpoint of the drawing) for oscillation within a vertical plane in accordance with the control exerted by its corresponding striker element 32 or 33, as the case may be. As illustrated, the bell crank is pivoted to a bracket arm 42a or 43a, extending perpendicularly outwardly of the corresponding bracket plate 42 or 43, its pivotal axis lying in a plane which is perpendicular to the plane in which plunger rod 30 moves. A

`trip arm portion 50a of the bell crank extends into the path of travel of the corresponding striker element of rod 30, while a tripper arm portion 50h extends through a suitably provided aperture of the bracket plate into the vicinity of the trip arm portion 5|a of a second bell crank 5|, such second bell crank being pivoted to the bracket plate on a vertical axis, that is to say so the pivotal axis is parallel to rod 30, for oscillation in a horizontal plane under the control of rst bell crank 50 and having a latch arm portion 5|b which engages the corresponding auxiliary plunger element 40 or 4|. The bracket arms 42a, and 43a are preferably struck from the bracket plates themselves, leaving the requisite apertures (desirably enlarged by suitable punch y operation) for accommodating the tripper armv portions 50h of respective bell cranks 50, see Figs. 2, 3, and 5, and Figs. 8, 9, and 10.

Associated with each bell crank 50 is a follower spring 52, constraining the trip arm portion 58a thereof to follow its striker element 32 or 33 whenever the travel of such striker element is receding, and associated with each bell crank 5| is a follower biasing spring 53, Fig. 2, constraining the trip arm portion 5|a thereof to follow the receding tripper arm portion 50h of the particular bell crank 50 concerned whenever the trip arm portion 50a thereof is actuated by its strikerI element on a positive stroke of the throw-rod 3l. The spring 52, it should be noted, is stronger than the spring 53 for eilecting'the results desired.

The unenerglzed ofP' position of the devicel is illustrated in Fig. l. There throw-rod 30 is maintained in its upwardly (from the standpoint of the drawing) thrown position by means of the spring disc 34, which is in its upward position of equilibrium, electrical contact 35 being in break position relative to its associated stationary load circuit contacts 26, 28. The two auxiliary plunger l* elements 40 and 4| are maintained in outward limit positions against the respective bracket plates 42 and 43 by means of coil spring 44, the intermediate ilxed plunger element 3| being maintained substantially against the upper auxiliary plunger element 40 and an air gap existing between such intermediate plunger element and the lower auxiliary plunger element 4|. So far as the latching mechanism is concerned, trip arm portion 50a of bell crank 55 of the upper latch assembly is completely tripped by 'striker element 32, thereby allowing latch arm 5|b of bell crank 50 of the same assembly tobe maintained in unlatching position relative to flange 40a of the 5 upper auxiliary plunger element 4t by reason ot the iniluence of its spring It, seev especially Pigs. 2 and 10. On the other hand, trip arm portion a f the lower latch assembly-18 mailltained in untrlpped position against its retracted striker element 38 by means of its spring l2, thereby maintaining latch arm IIb of the same assembly in latching position overlying nange a oi' the lower auxiliary plunger element 4I against the iniluence of its spring 53, see Fig. 3. (Fig. 8 also illustrates this condition, though inverted since it deals with the upper latch assembly.)

The energized -on position occurs when the push button or other controlinstrumentality of the control circuit (not shown) is actuated. thereby energizing the solenoid coil I1. This -oocurs only momentarily, but is sufllclent to throw the throw-arm 30 to eifective position, the positions ofthe several parts being as illustrated in Fig. 4. The cessation of actuation of the control instrumentality, as for instance the release of the push button, de-energizes the solenoid coil, and the several parts assume the positions of Fig.

6.` Re-actuation produces the energized ol position of Fig. 7', while cessation of such re-actuation returns the device to the unenergized olf position of Fig. 1.

In the energized on position of Fig. 4, throwarm 30 has been thrown downwardly by action of energized solenoid coil I1, so that electrical contact 35 makes with the stationary load circuit' contacts 26, 26. Spring disc 34, ilipped as it is to its opposite position of equilibrium, is now in position to maintain throw-arm 30 downwardly, as thrown. Because of their mutual adjacency, auxiliary plunger element 40 and intermediate plunger element 3| have been moved downwardly as a unit; auxiliary plunger element 4l has been restrained by latch arm 5Ib from movement upwardly under the influence of the magnetic flux of the solenoid coil. By the time the throw-rod assumed its downward position, however, the trip arm portion 50a of the lower latch assembly was tripped by striker element 33, so that the latch arm portion 5|b thereof has been moved to its non-latching position. Trip arm portion 50a of the upper latch assembly tried to completely follow the receding striker element 32 by reason of the urge of spring 52, but was stopped midwaybecause the latch arm portion Sib of the associated bell crank 5I struck flange 40a of the downwardly displaced auxiliary plunger element Il, as shown, and could not complete its full strike, see also Figs. 5 and 9.

Upon de-energization of the solenoid coil the device assumes the unenergized on position of Fig. 6, wherein auxiliary plunger element 43 has been displaced upwardly to its normal limit posivtion against bracket plate 42 and the aforementioned latch arm portion 5th has snapped into latching position under flange 40a thereof.

In both the energized on position of Fig. 4 and the unenergized on position of Fig. 6 lthe lower latch assembly is unlatched; the latter position is just the reverse 'of the unenergized "oil'" position of Fig. l.

The energized off position oi Fig. 7 is just the reverse of the energized onf position of Fig. 4, the latch arm portion 5i b of the lower latch assembly, in this instance; having struck the ilange lla of the auxiliary plunger element 4I, thereby preventing the trip arm portion Sla of the bell crank 50 from following the upwardly receding striker element 33, as illustrated.

Following this energized olT ergization of the solenoid coil il permits coil spring M to return the device to the unenergized "oiT position of Fig. 1, whereupon the device is 5 in condition for repetition of the aforementioned operative cycle.

Whereas this invention is here illustrated and described with respect to a preferred speciilc construction thereof it should be understood that various changes may be made therein and various other constructions may be produced on the basis oi' the teachings hereof by those skilled in the art, without departing from the generic scope of the invention as deilned by the following claims.

l5 We claim:

l. In combination, a solenoid coil; a plunger,

arrangement mounted in said coil and operable thereby, said plunger arrangement comprising an elongated plunger rod, an intermediate plunger element of magnetic material fixed to said rod, and respective auxiliary plunger elements of magnetic material freely mounted on said rod at opposite ends of said intermediate plunger element for longitudinal movementl along said rod; respective stops xed with respect to said solenoid coil limiting the extent of outward movement of said auxiliary plunger elements relative to said intermediate plunger element; resilient means extending between said auxiliary plunger elements normally urging said elements against their respective stops; double equilibrium means ilxed with respect to said solenoid coil and with respect to said plunger rod for maintaining said plunger rod in the alternate positions to which it is thrown by successive energizations of said solenoid coil, said alternate positions placing the intermediate plunger element closely adjacent one or the other of the auxiliary plunger elements and coincidentally producing a gap between it and the opposite auxiliary plunger element; oppositely disposed striker means associated with said plunger rod; and oppositely disposed latch assemblies pivoted respectively to said stops and engageable respectively with said auxiliary plungers for alternating locking against movement when the solenoid coil is energized the one of said auxiliary plunger elements which is not adjacent said intermediate plunger element, each of said latch assemblies embodying a system of levers having a trip arm extending into the path oi' movement of one ot said striker means, and a latch arm responsive to the movement of said trip arm and operative to engage one of said auxiliary plunger elements so as to restrain movement thereof.

2. The combination recited in claim l wherein each latch assembly comprises a bell crank having a pivotal axis lying within a plane which is substantially perpendicular to the plane within which the plunger rod moves, a second bell crank w having a pivotal axis substantially parallel with said plunger rod, one arm of the first bell crank n providing the trip arm which extends into the path of movement of a striker means, one arm of the second bell crank providing the latch arm 65 which engages an auxiliary plunger element, and

the other arms of the said bell cranks being disposed relative to each other to effect correlated movement of the two bell cranks in the operation of the combination, a follower spring operative on the rst bell crank, and a follower spring operative on the second bell crank.

3. The combination recited in claim l wherein the respective stops are bracket plates mounted at opposite ends of the solenoid coil, the plunger rod l7| operatively extending through said bracket position, de-enplates. and wherein the respective latch assemblies are mounted on said bracket plates. l

4. The combination recited in claim 1, wherein the means for maintaining the plunger rod in the alternate positions to which it is thrown by successiveenergizations of the solenoid coil is a double equilibrium spring disc.

5. In an electrical relay having a solenoid coil and composite plunger means, said means including a plurality of plungers of magnetic material co-axially in line and movable one against the next, said means being-operative as an armature,

. latch means operative on the plunger means,

comprising a pair of coacting bell cranks mounted for mutually correlated movement, one oi.' said bell cranks having a resilientlypositione trip arm which is arranged to be tripped by a given movement of the plunger means, and the other latch arm normally maintained in latching engagement with a component of said plunger.

means; tripping of the trip arm of one of said bell cranks eil'ecting unlatching of the latch arm of the other of said bell cranks. v

6. In a solenoid having a composite plunger, including a plurality of plunger 'elements of magnetic material coaxially in line and movable one against the next, 'as an armature, a latch operative to restrain movement oi one element of the composite plunger, said latch comprising a bell ,o

crank pivoted to engage and latch an -element of `oi" said bell cranks having a resiliently biased `-said second bell crank having a trip arm portion thereof extending` into the path of a second plunger element for movement thereby against the action of said'strong spring to release said rst-named bell crank.

l JOSEPH F. O'BRIEN.

JOHN B. CATALDO.

REFERENCES CITED The following references are of record in the ille of this pmnt:

UNIIED STATES PATENTS Date Number Name 4 1,257,613 Kocourek Feb. 16, 1918 1,449,212 Berry Mar. 20, 1923 v1,595,757 Coates Aug. 10. 1928 2,417,438 OBrien et al Mar. 18, 1947 FOREIGN PATENTS Number Country` Date v G reat Britain Dec. 27, 1933

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