US2261818A - Electromagnetic relay - Google Patents

Description

Nov. 4, 1941. woo 2,261,818

ELECTROMAGNETIC RELAY Filed June 15, 1939 I195 u/afion INVENTOR.

Fredric E. Wood BY ATTORNEYS Patented Nov. 4, 1941 2,261,818 ELECTROMAGNETIC RELAY Fredric E. 'Wood, on Park, 111., assignor to Associated Electric Laboratories, Inc., Chicago, 11]., a corporation of Delaware Application June 15, 1939, Serial No. 279,315

1 Claim.

The present invention relates to electromagnetic devices and moreparticularly to electromagnetic relays of the switching type.

An electromagnetic relay conventionally comprises a field structure including a core provided with a winding, a movable armature carried by the field structure, and a set of switch springs operatively connected to the armature.

It is an object of the present invention to provide an improved relay of the type described, which is of rugged and economical construction and which is reliable and positive in operation.

Another objectof the invention is to provide, in a relay of the type described, an improved arrangement for pivotally mounting the armature on the fleldstructure and for locking the armature in place. I c

In brief, the objects set forth above are in part realized in accordance. with one feature of the present invention by providing an electromagnetic relay comprising a longitudinally extending core, a substantially L-shaped field element including a first laterally and forwardly extending leg secured to one end of the core and a second longitudinally extending leg arranged in spacedapart relation with respect to the core, and an armature. An arrangement including integral lugsprovided on the outer end of the secondleg of the field element and cooperating openings provided in the armature adjacent the inner end thereof is utilized for pivotally mounting the armature on the outer end of the second leg and.

. in cooperating relationship with respect to the outer end of the core, 'Further,=a substantially L-shaped bracket is provided which includes a first longitudinally extending arm secured to the second leg of the field element and a second laterally and rearwardly extending arm. A laterally and forwardly extending projection is carried by the second arm of the bracket which engages the ends of the lugs provided'on the outer end of the second leg of the field element, thereby to lock the armature in place on the outer end of the second leg. Further the second arm of the bracket carries a spring which engages the amiature in order to urge the armature in seated enj gagement withthe outer end of the second leg of the field element.and a stop for limiting the pivotal movement of the armature away from the outer'end of the core. Finally, the second arm carried thereby comprises a link formed of a suitable insulating material. The armature is connected to the link by an arrangement including an integral lug provided on the outer end of the armature and a cooperating opening provided in the link, the lug projecting through the cooperating opening and extending inwardly to provide an inwardly directed seat arranged to receive and engage the wall of the link adjacent the cooperating opening. Similarly, one of the switch springs of the set of switch springs is connected 7 to the. link by an arrangement including an integral lug provided on the outer end'of the switch spring and a cooperating opening provided in the link, the lug projecting through the cooperating opening and carrying outwardly extending spaced-apart fingers to provide an outwardly directed seat arranged to receive and engage the wall of thelink adjacent the cooperating opening.

Finally the lugs respectively provided on the outer end of the armatureand on the outer end of the switch spring and the respective cooperating openings provided in the link are so constructed and arranged that they are readily engageable and disengageable, thereby to facilitate ready placement and removal of the link.

Further features of the invention pertain to the I particular construction and arrangement of the elements of the relay whereby the above-outlined and additional operating features are attained.

The novel features believed to be characteristic of the invention are set forth with particularity,

in the appended claim. The invention, both as to its organization and method of operation, to-

gether with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawing, in which Figure 1 is a plan view of an electromagnetic relay constructed and arranged in accordance with the present invention; Fig. 2 is a longitudinal sectional view of the relay taken along the line 2-2 in Fig. 1; Fig. 3 is an end elevational view of the relay shown in Fig. 1; and F lg. 4 is a fragmentary exploded perspective view of the relay illustrating the mounting arrangement for the armature thereof.

Referring now more particularly to Figs. 1 to 3, inclusive, of the drawing, the electromagnetic relay there shown comprises a field structur including a longitudinally extending core l0 provided with a winding H and a substantially L- shaped field element i2 including a first laterally and forwardly extending leg l3 secured to .one' end of the core HI by a screw l4, extending through an opening provided in the leg l3 and threaded into a tapped hole provided in the end of the core ID, and a second longitudinally ex tending leg l5 arranged in spaced-apart relationship with respect to the core Ill. The winding H surrounds the core Ill and is retained in place by a pair-of spaced-apart retaining heads l6 and I1 arranged on the opposite ends of the winding II and surrounding the core ID, th retaining heads l6 and I! being formed of a suitable insulating material.

Also the relay comprises a movable armature l8 and a substantially L-shaped bracket IS including a first longitudinally extending arm 20 and a second laterally and rearwardly extending arm 2|. As best shown in Figs. 2 and 4 of the drawing, the inner end of the armature I8 is pivotally mounted on the outer end of the leg l5 intervening strips 34 of a suitable insulating and the arm is secured to the leg |5 by two screws 22 extending through openings provided in the arm 20 and threaded into tapped holes provided in th leg l5. The arrangement for pivotally mounting the inner end of the armature IS on the outer end of the leg l5 comprises interfitting lugs respectively carried on the outer end of the leg |5 and on the inner end of the armature I8. Specifically, the intermediate portion of the outer end of the leg I5 is cut out to provide two lugs 23 spaced apart by an intervening notch 24; while the opposite sides of the armature l8 adjacent the inner end thereof are cut out to provide two spaced-apart lugs 25 and associated spaced-apart notches 26. Also the intermediate portion of the inner end of the armature I8 is cut out to provide a notch 21 disposed intermediate the two spaced-apart lugs 25. When the field element l2, the armature I8 and the bracket H are in assembled relationship the two spaced-apart lugs 23 provided on the leg I! extend into and project through the two spacedapart notches 26 provided in the armature l8; andthe intermediate portion of the armature I8 is disposed in the notch 24 provided in the leg l5. Furthermore, the notch 21 provided in the armature l8 receives the leg 20.

The order to lock the inner end of the armature IS in place on the outer end of the leg IS, an arrangement is provided which comprises two spaced-apart laterally and forwardly extending projections 29 carried by the arm 2| of the bracket I9. More particularly, the two spacedapart projections 29 carried by the arm 2| of the bracket l9 overlie and directly engage the ends of the two spaced-apart lugs 23 carried by the leg l5 of the field element l2. This arrangement positively locks the inner end of the armature IS in place on the outer end of the leg l5; yet, it provides for'ready removal or the armature I8. This may be accomplished merely by unthreading the screws 22 from th tapped holes provided in the leg |5 and then removing the bracket l3, whereupon the inner end of the armature l3 may be removed from the outer end of the leg IS in an obvious manner.

In addition to providing an arrangement for locking the inner end of the armature IS on the outer end of the leg IS, the arm 2| of the bracket l9 carries a leaf spring 30, a stop 3|, a set of switch springs 32 and a clamping plate 33 in stacked relationship. Specifically, the leaf spring 30 is arranged directly upon the arm 2|, the stop 3| is arranged upon the leaf spring 30, and the switch springs of the set of switch springs 32 are separated from each other and from the stop 3| and the clamping plate 33 by material. Finally the clamping plate 33, the switch springs of the set of switch springs 32, the strips 34 of insulating material, the stop 3|, and the leaf spring 30 are retained in assembled and stacked relationship by twoscrews 35 extending through aligned openings provided therein and threaded into tapped holes provided in the arm 2|. The set of switch springs 32 is illustrated as comprising two switch springs 35 and 31, although it will be understood that the set of switch springs 32 may comprise any reasonable number of switch springs. Furthermore, it is noted that the arm 2| of the bracket H has two sets of spaced-apart openings 2|a and 2| 1) provided therein which are disposed on opposite sides of the set of switch springs 32, these two sets of openings being arranged to fasten two additional sets of switch springs to the arm 2| or to fasten the arm 2| on a suitable support, as desired. When the two sets of opening 2| a and 2|b provided in the arm 2| of the bracket l9 are utilized to fasten the arm 2| to a support, the entire weight of the relay is supported by the arm 2|. Th switch springs 36 and 31 are respectively provided with terminals 36a and 37a to which electrical connections may be extended, and carry cooperating contacts adjacent the outer ends thereof, which are arranged in switching relationship and preferably formed of a suitable precious metal.

The leaf spring 30 is provided with an outwardly projecting and inwardly curved end 30a arranged in direct engagement with the inner end of the armature l8, thereby to urge the inner end of the armature l8 into seated engagement with the outer end of the leg I5 and to prevent longitudinal movement therebetween incident to the pivotal movement of the armature l8 away fromthe cooperating outer end of the core HI. Also the stop 3| is provided with an outwardly projecting and inwardly directed end 3|a which cooperates with the armature l8 to limit the pivotal movement of the armature l8 away from the outer end of the core I. Furthermore, the armature II has an opening provided therein, into which a rivet, 33 formed of nonmagnetic material is securely fastened, the rivet 33 being arranged to engage the outer end of the core Ill when the armature I3 is moved toward the core Ill, The arrangement of the rivet 33 carried by the armature 8 with respect to the outer end of the core I prevents the armature I8 from sticking to the outer end of the core I0 when the armature I8 is moved toward the outer end of the core incident to the energization of the winding In order operatively to connect the armature l8 and .the movable switch spring 36 of the set of switch springs 32, an arrangement is provided which comprises a link 33 formed of a suitable insulating material. More particularly, the link 39 has a pair of spaced-apart openings 40 formed therein adjacent the inner end thereof and a centrally disposed opening 4| formed therein ad- .jacent the outer end thereof, the opening 4| being arranged intermediate and in spaced-apart relationship with respect to the two openings 40. Two integral lugs 42 are provided on the outer end of the armature |3, these lugs being arranged to project through the cooperating openings 40 provided in the link 33. Similarly, an integral lug 43 is provided on the outer end of the switch spring 36, this lug being arranged to project through the cooperating opening 4| prospring 36 carries integral and outwardlylextending spaced-apart fingers 44 which provide an outwardly directed seat arranged to receive and engage the wall of the link 39, adjacent the opening provided therein.

The lugs 42 provided on the outer end of the armature It, the lug 43 provided on the outer end of the switch spring 33, and the cooperating openings 49 and 4| provided inthe link 39 are so constructed and arranged that they are readily engageable and disengageable; thereby to iacilitate ready placement and removal of the link 39. More particularly, the link 39 may be readily removed by forcing the switch spring 36 inwardly, thereby to disengage the outwardly directed seat provided in the lug 43 and the associated wall of the link 39 adjacent the cooperating opening 4|, and then by swinging the link 39 away from the switch spring 33. The inwardly directed seats provided in the lugs 42 and the. associated walls of the link 39 adjacent the cooperating openings 40 may then be disengaged, in an obvious manner, in order to permit the link 39 to assembly.

Furthermore, it is noted that two spaced-apart slots 45 are provided on the opposite sides of the link 39 adjacent the outer end thereof, these slots being arranged to accommodate the two-cobe completely removed from the v operating lugs provided on the two switch springs of the two sets of switch springs, in the event the relay comprises three sets of switch springs,

as previously noted, More particularly, the two sets of switch springs, which may be secured to the arm 2| of the bracket H! by utilizing the two sets of aligned openings 2-la and 2|b formed in the arm 2|, may be operatively connected to the link 39 by utilizing the slots 49 provided therein, in the manner previously explained.

In assembling the relay, the leg ll of the field element I2 is first secured to the core ID with the screw l4, and the winding II is then placed upon the core l0. Subsequently, the inner end of the armature I8 is positioned on the outer end of the leg l5 of the field element l2, and

.the bracket I9 is secured in place, thereby to lock the inner end of the armature ll upon the outer end of the leg I5. Thereafter, the leaf spring 30, the stop 3|, the set of switch springs 32, the insulating strips 34 and the clamping plate 33 are assembled upon the arm 2| of the bracket l9 in an obvious manner, the engagement. between the outer end 30a of the leaf spring 30 and the inner end of the armature l3 retaining the inner end of the armature II in seated engagement with the outer end of the leg it. Finally, the armature I3 is operatively connected to the switch spring 33 by placing the link 39 in its cooperating position with respect to the lugs 42 and 43 respectively provi ed on the outer ends of the armature l3 and spring 33'.

Normally the switch spring 33 exerts a force e switch the winding II is energized, the magnetic flux traversing the core III, the fleld element l2 and the armature |8 causes the armature I! to be moved toward the outer end of the core ill, the inner end of the armature l8 being pivoted in a clockwise direction, as viewed in Fig. 2, about the outer end of the leg I! of the field element l2. This movement of the armature l8 toward-the outer end of the core I9 is transmitted by the link 39 to the switch spring 36, in order to cause the contacts carried by "the switch springs 38 and 3'! to be moved into engagement; When the winding H is deenergized the switch spring 33 then moves the armature ll away from the outer end of the core It, the inner end of the armature I8 being pivoted in a counterclockwise direction, as viewedin' Fig. 2. about the outer end of the leg ii of the field element l2. When the switch. spring 33 returns .to its normal position the set ofcontacts carried by the switch springs 38 and 31 are moved into disengagement. Accordingly,

the movement of the armature I9 is controlled Jointly by the energization of the winding l I and 'the resiliency of the switch spring 38; and the armature is prevented from sticking to the outer end of the core l9 due to any residual magnetism in the core I. by the rivet 33 formed of nonmagnetic material.

In view of the foregoing it is apparent that an improved electromagnetic switching relay is provided which is of rugged andeconomical construction and which is reliable and positive in operation.

While there has been described what isat present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to coverrin the appended claim all such modifications as fall within the'true' integral lugs provided on the outer end of said through the link 33 upon the outer end the armature I3, thereby to restrain the armature l3 away from the outer end of the core II and toward the outer end an; of the stop a. when second leg and cooperating openings provided in said armature adjacent the inner end thereof for pivotally mounting the inner end of said armature on the outer end of said second leg and incooperating relationship with respect to the outer end of said core, a substantially L-shaped bracket Y including a first longitudinally extending arm removably secured to said second leg and a second laterally and rearwardly extending arm, means including a laterally and forwardly extending projection carried by said second arm and engaging the ends of said lugs for locking the inner end of said armature in place on the outer end of said second leg, means including a leaf spring carried by said second arm and pro- Jecting forwardly into engagement with said armature for urging the inner end of said armature in seated engagement with'the outer end of said second leg, and means including a stop carried by said second arm and projectlng'forwardly over said armature for limiting the pivotal movement of said armature away from the outer end of said core.

FREDRIC E. WOOD-

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