US2908785A

US2908785A - Electromagnetic device

Info

Publication number: US2908785A
Application number: US736111A
Authority: US
Inventors: Robert D Stayton
Original assignee: RICKERT ELECTRIC Inc
Current assignee: RICKERT ELECTRIC Inc
Priority date: 1958-05-19
Filing date: 1958-05-19
Publication date: 1959-10-13
Anticipated expiration: 1976-10-13

Description

Oct. 13, 1959 R. D. STAYTON 2,908,735

ELECTROMAGNETIC DEVICE Filed May 19. 1958 2 Sheets-Sheet 1 FIGI.

Oct. 13, 1959 R. D. STAYTON ELECTROMAGNETIC DEVICE 2 Sheets-Sheet 2 Filed May 19, 1958 FIGS.

United States Patent fiFice 2,908,785 Patented Oct. 13, 1959 ELECTROMAGNETIC DEVICE Robert D. Stayton, St. Louis, Mo., assignor to Rickert Electric, Inc., St. Louis, Mo., a corporation of MIS- sour-i Application May 19, 1958, Serial No. 736,111

6 Claims. (Cl. 200-104) This invention relates to electromagnetic devices, and more particularly to an electromagnetic relay.

Among the several objects of the invention may be noted the provision of an electromagnetic device, and more particularly a relay, of a type comprising a frame which constitutes a magnetic core, and also comprising an armature and a coil, wherein the frame or core provides a closed magnetic circuit surrounding the coil for maximum electromagnetic efiiciency, and which is of relatively simple and inexpensive construction; and the provision of a device of this character which is of such construction as to minimize the retarding etfect' on the armature of any residual magnetism which may remain in the core and armature upon deenergization of the coil so that movement of the armature upon deenergization of the.

coil is not impeded. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. 1 is a plan view of a relay of this invention;

Fig. 2 is a side elevation of Fig. 1;

Fig. 3 is a right end elevation of Fig. 2;

Fig. 4 is a left end elevation ofFig. 2;

Fig. 5 is a section taken on line 55 of Fig. 4;

Fig. 6 is a perspective view of the core per se of the relay in a tilted position for best illustration; and,

Fig. 7 is a perspective view of the armature per se of the relay in a tilted position corresponding to Fig. 6.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, a relay made in accordance with this invention is shown to comprise a magnetic frame or core 1, a magnetic armature 3, an electromagnetic coil 5 and a set of contacts 7. The frame or core 1 is of special construction to provide a completely closed magnetic circuit around the coil 5 for maximum electromagnetic efficiency. This construction and the construction of the armature 3 are also such as to minimize the retarding effect on the armature of any residual magnetism Which may remain in the core and armature upon deenergization of the coil, so that quick-opening of the contacts upon deenergization of the coil is assured.

The core 1 (illustrated per se in Fig. 6) is essentially of open rectangular form, two opposite sides of the core constituting first and

second core legs

9 and 11, the other two sides constituting first and

second core yokes

13 and 15. The first leg 9 has a central slot 17 (see Figs. 4 and 6) and the first yoke 13 has a central slot 19 (see Figs. 5 and 6), these slots meeting at the corner 21 of the core where the first leg 9 and first yoke 13 meet. The coil 5 is secured to the second core leg 11 within the core and extends from the second leg 11 toward the slot 17 in the first leg 9. The armature 3 (illustrated per se in Fig. 7) has first and

second arms

23 and 25 generally at right angles to one another, the Width thereof being slightly less than the Width of slots 17 and 19. The armature is mounted for swinging movement on a transverse axis at the juncture of its

arms

23 and 25 and at the corner 21 of the core, with the first arm 23 extending in the slot 17 and having an end portion opposed to the end of the coil, and with the second arm 25 extending in the slot 19. Arm 25 is longer than arm 23 and projects beyond the core leg 11.

More particularly, the core 1 is of two-piece construction, one piece being designated 27 and the other 29. These pieces, as well as the armature, are sheet metal stampings made from magnetizable sheet metal such as soft steel. The first piece 27 is formed to have a rectangular base plate portion 31 having holes 33 therein for receiving fasteners such as screws (not shown) for attaching the relay to a support (not shown). Bent to extend at right angles from one edge 35 of the rectangular base plate portion 31 are two laterally spaced-apart members 37 which constitute the first leg 9 of the core 1 and between which is the slot 17. Bent to extend at right angies from the ends of the leg members 37 are laterally spaced-apart first yoke members 39 between which is the slot 19. Extending centrally from edge 35 of the base plate portion 31 coplanar with the latter is a tongue which constitutes the second yoke 15 of the core. This tongue 15 is obtained from the portion of the sheet metal blank from which the first core piece 27 is formed originally lying between the two members 37 and the two members 39. Tongue 15 has a hole 41.

The second piece 29 is of L-shape, having a fiat rectangular portion which constitutes the second leg 11 of the core, and laterally spaced-apart yoke members 43 bent to extend at right angles from one edge 45 of leg 11. The width of leg 11 corresponds to the overall width of leg 9. The width and spacing of yoke members 43 corresponds to the width and spacing of yoke members 39. Members 43 are formed with offset end portions 47. Projecting from the edge 49 of leg 11 opposite its edge 45 is a central tang 51 which is received in hole 41 in tongue 15.

The armature 3 is formed with laterally projecting pivots 53 at the juncture of its

arms

23 and 25, and with cutouts 55 at the sides of arm 25 adjacent the pivots. The pivots are located within the corner 21 of the core and are retained therein by the offset end portions 47 of yoke members 43, the latter being applied to the inside of members 39 and secured thereto by bolts 57. These bolts pass through bolt holes in members 39 and 41 and also serve to secure in place on the outside of members 39 the contact assembly 7. As shown, this contact assembly comprises three sets of three spring arms each, the arms of the first set being designated 59, the arms of the second and intermediate set being designated 61, and the arms of the third set being designated 63. These arms are clamped by the bolts 57 between insulation plates 64 and project out beyond the leg 11 of the core. The intermediate arms 61 are longer than and project beyond the

other arms

59 and 63. Contacts such as indicated at 65 are provided adjacent the free ends of the arms. Arm 25 of the armature has an insulation plate 67 at its free end engaging the free ends of the intermediate spring arms 61.

Leads for the coil 5 are indicated at 69. The coil is shown as wound on a core 71 having one end riveted as indicated at 73 in a hole '75 in leg 11. When the coil is deenergized, the inherent spring bias of arms 61 holds the armature in the retracted position in which it is shown in Figs. 2 and 4, the contacts on arm 61 being in engagement with the contacts on arms 59 and clear of the contacts on arms 63. The retracted posi tion of the armature is determined by the engagement of armature arm 25 with the bottom of a notch 77 in edge 3 45 of the core leg 11. When the coil is energized, the armature is swung counterclockwise as viewed in Fig. 2 to bring the contacts on arms 61 into engagement with the contacts on arms -.63 and clear of the contacts on arms 59. The core constituted by the first leg members ,37, the

first yoke members

39 and 43, the second leg member 11 and the second yoke member or tongue 15 completely surrounds the coil for maximum electromagnetic efficiency. The cutouts 55 at the sides of annature arm 25 provide arm 25 with a constricted portion 79 thereby minimizing the tendency of any residual mag netism in the core and armature (which may remain .therein upon deenergization of the coil) to make the armature hang up in its operative position and delay its opening. Thus, quick retraction of the armature upon deenergization of the coil is assured.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. An electromagnetic device comprising a core of open rectangular form made of magnetizable sheet metal, two opposite sides of the core constituting first and second core legs and the other two sides constituting first and second core yokes, the first leg and the first yoke each comprising two laterally spaced-apart members, an electromagnetic coil within the core, an armature made of magnetizable sheet metal having first and second arms generally at right angles to one another, said armature being pivotally mounted for swinging movement on a transverse axis at the juncture of said arms and at the corner of the core where the first leg and first yoke meet, the first arm extending between the spaced-apart first leg members and having an end portion opposed to the end of the coil, and the second arm extending between the spaced-apart first yoke members, said core being a two-piece core, the first piece comprising a base plate portion, two laterally spaced-apart members extending generally at right angles to the base plate portion at one edge of the latter and constituting the said spaced-apart first leg members, two laterally spacedapart members extending generally at right angles to said spaced-apart first leg members from the ends of the latter and constituting first yoke members, and a tongue extending centrally from said edge .of the base plate portion generally coplanar with the base plate portion and constituting the second yoke, the second piece comprising a flat plate portion constituting the said second leg of the core, and two laterally spaced-apart additional first yoke members extending generally at right angles to-said second leg at one edge of the latter and secured to the spaced-apart first yoke members of the first piece. 2, An electromagnetic device as set forth in claim 1 wherein the spaced-apart first yoke members of the second piece extend on the inside of the spaced-apart first yoke members of the first piece, and the armature is pivotally mounted by means of laterally projecting pivots at the juncture of its arms, these pivots being confined within said corner of the core by offset end portions of said spaced-apart first yoke members of the second piece.

3. An electromagnetic device as set forth in claim 2 wherein said second leg is connected to said tongue.

4. An electromagnetic relay comprising a core of open rectangular form made of magnetizable sheet metal, two opposite sides of the core constituting first and sec ond core legs and the other two sides constituting first and second core yokes, the first leg and the first yoke each comprising two later-ally spacedapart members, an electromagnetic coil secured to the second leg within the core and extending toward the first leg, an armature made of magnetizable sheet metal having first and second arms generally at right angles to one another, said armature being pivotally mounted for swinging movement on a transverse axis at the juncture of said arms and at the corner of the core where the first leg and first yoke meet, the first arm extending between the spacedapart first leg members and having an end portion opposed to the end of the coil, and the second arm extending between the spaced-apart first yoke members and projecting beyond said second leg, and a set of contacts mounted on the core, and means at the end of said second arm engageable with said set of contacts, said cor-e being a two-piece core, the first piece comprising a flat base plate portion, two laterally spaced-apart members extending generally at right angles to the base plate portion at one edge of the latter and constituting the said spaced-apart first leg members, two laterally spaced-apart members extending generally at right angles to said spaced-apart first leg members from the ends of the latter and constituting first yoke members, and a tongue extending centrally from said edge of the base plate por tion generally coplanar with the base plate portion and constituting the second yoke, the second piece comprising a fiat rectangular plate portion constituting 'the said second leg of the core, and two laterally spaced-apart additional first yoke members extending generally at right angles to said second leg at one edge of the latter and secured to the spaced-apart first yoke members of the first piece by means also securing the set of contacts to the core.

5. An electromagnetic relay as set forth in claim 4 wherein the spaced-apart first yoke members of the second piece extend on the inside of the spaced-apart first yoke members of the first piece, and the armature is pivotally mounted by means of laterally projecting pivots at the juncture of its arms, these pivots being confined within said corner of the core by ofiset end portions of said spaced-apart first yoke members of the second piece.

6. An electromagnetic relay as set forth in claim 5 wherein the second leg has a tang at the edge thereof opposite its said one edge received in a hole in said tongue.

References Cited in the file of this patent UNITED STATES PATENTS 1,114,225 Cahusac Oct. 20, 1914 1,904,847 Babbitt Apr. 18, 1933 2,339,610 Baker Jan. 18, 1944 2,790,045 Roesen Apr. 23, 1957