US2749396A - Contact structure for relays and the like - Google Patents

Description

June 5, 1956 J, H, HORMAN ET AL 2,749,396

CONTACT STRUCTURE FOR RELAYS AND THE LIKE Original Filed Feb. 28, 1952 2 Sheets$heet l /nven fors John H Harman Edward C, Hoe// W, Wow/( 1 26 Affomeys June 5, 1956 J. H. HORMAN ET AL 2,749,396

CONTACT STRUCTURE FOR RELAYS AND THE LIKE 2 Sheets-Sheet 2 Original Filed Feb. 28, 1952 United States Patent CONTACT STRUCTURE FOR RELAYS AND THE LIKE John H. Harman, Tuckahoe, and Edward C. Hoell, New York, N. Y., assignors to Allied Control Co., Inc, New York, N. Y., a corporation of New York Original application February 28, 1952, Serial No. 273,692. Divided and this application January 2, 1953, Serial No. 329,284

4 Claims. (Cl. 200-1) This invention relates to electromagnetically operated 1 switch mechanisms, often called relays.

This application is a division of our copending application Ser. No. 273,962, filed February 28, 1952, and is directed to the construction and arrangement of the contact members of the relay therein described.

The objects of the invention, hereinafter defined in the claims, are:

(a) To provide an improved contact arm arrangement which enables a large number of switch units to be arranged in a small space;

(1)) To provide movable contact springs having the desired spring rate with a relatively short over-all length;

(c) To provide contact arm mounting means facilitat ing assembly and of rugged construction requiring no internal wiring and having low internal resistance; and

(d) A novel contact arrangement permitting simultaneous operation of several switch units by a single actuator of small dimension.

Other objects and advantages will in part appear and in part will be obvious from the following detailed description of a relay embodying the invention, taken in conjunction with the drawings, in which:

Fig. l is a central sectional elevation of a relay embodying the invention, taken on the line 1-1 of Fig. 2; Fig. 2 is a plan view of the inside of the terminal header supporting the contact arms;

Fig. 3 is a perspective view of one of the movable contact arms showing the curvature of its end portion;

Fig. 4 is a section on the line 4-4 of Fig. 3;

Fig. 5 is a sectional elevation, similar to but on a smaller scale than Fig. l and at a different angle, taken on the line 5-5 of Fig. 6, showing the ends of the magnetizing coil of the relay secured to terminals;

Fig. 6 is a plan view looking at the opposite side of the terminal header from that shown in Fig. 2;

Fig. 7 is an exploded view of the various parts of the relay;

Fig. 8 is an exploded view showing how the armature and its associated parts may be assembled; and

Fig. 9 is a detail, partly in section, of the means for mounting the contacts.

The magnetic structure of the relay, best shown in Figs. 1 and 7, will be briefly described to show how the contact structure is actuated. Magnetizing coil 10 is enclosed within identical annular cup-shaped pole- pieces 12 and 14, the outer edges of which engage one another at 16, and the inner edges of which are spaced apart providing a gap 18 located within the magnetizing coil. Insulating washers or disks 20 are inserted in the bottoms of the pole- pieces 12 and 14. Pole-piece bushing 22 of magnetic material is forced into the pole-piece 14, the length of said pole-piece bushing 22 being such that its inner end lies adjacent the gap 13 and its diameter being such as to have a press fit in pole-piece 14. Shell 24, of nonmagnetic material, is inserted into the opening in the other pole-piece 12, serving as a bearing for movable armature 26.

Armature 26 is arranged to slide within the brass shell 24 in cooperative relation to the pole-piece bushing 22 and the gap 18. Within armature 26 and biasing it to its normal position away from the pole-piece bushing (as shown in Fig. l) is a tension spring 28 attached at one end to the armature 26 by several crimped portions 30, and at its other end to head 31 of a screw 32 threaded into a brass end-plate 34 from which the threaded end 33 of the screw 32 initially projects. The end-plate 30 is provided with openings 36 adapted to cooperate with lugs 38 punched from the bottoms of pole- pieces 12 and 14. Thus, there is provided an armature assembly in which the spring 28 and screw 32 serve to bias the armature 26 toward its normal position as shown in Fig. 1, but permits movement of the armature 26 within the brass shell 24 toward and into engagement with the pole-piece bushing 22 when the magnetizing coil 10 is energized.

Slidingly mounted within bushing 22 is an actuator 42 of rigid insulating material. its upper end normally projects beyond bushing 22 in a position to be engaged by armature 26. The movement of the actuator 42 within the pole-piece bushing 22 toward the armature 26 is limited by a flange 44 which engages the end of the polepiece bushing 22 as shown. The amount of possible movement of the actuator is governed by the distance it projects beyond bushing 22. Flange 44 also serves to actuate the contact members of the relay, as hereinafter described, and is formed with a groove as shown to facilitate performance of that function. At its outer end actuator 42 is provided with a cavity which contains a light compression spring 46 which engages the center of disk 48 of the terminal header assembly (hereinafter described) and serves to hold the actuator 42 against bushing 22.

Secured to pole-piece 14, preferably by spot welding, is a bracket 50 the form of which is best shown near the bottom of Fig. 7. This bracket 50 is provided at its center with an opening 52 which receives the end of bushing 22, and with openings 54 which cooperate with lugs 33 on the pole-piece 14, thereby facilitating proper positioning of the bracket 50. The arms 56 of the bracket engage at their outer ends with notches 58 in the disk 48 of the header. Thus disk 48 is secured in spaced relation to magnet shell 14, thereby providing a space for a plurality of movable and fixed contact members carried by the disk 48 and arranged as described below.

The construction of the terminal header assembly is best shown in Figs. 1, 2 and 6. The disk 48 is provided with a plurality of holes arranged in two circles around the center of said disk, the number of holes in the outer circle being double the number of holes in the inner circle. Contact terminals 60 are secured in the holes in the outer circle, and contact terminals 62 are secured in the holes in the inner circle, by the use of a suitable rigid insulating material such as glass as best shown in Fig. 1 at 64. That is, the contact terminals 60 and 62 are mounted in the disk 48 and are insulated from it and from one another. Mounted in the same way in holes in the disk 48, are the two terminals 66 and 68 to which are secured the leads 70 and 72 of the magnetizing coil 10, as shown in Fig. 5 from which it will be apparent that the wires 76 and 72 pass through notches 73 (Fig. 7) in the edges of the disks 20, through openings 74 and 76 in the polepiece 14, and through notches 77 and 78 in the bracket 50.

As will be evident from Figs. 1 and 2, groups of cooperating contact members are mounted on the terminals 60 and 62. Each of these groups of cooperating contact members includes a U-shaped movable contact member 79 (Fig. 3) which is secured at one end to a terminal 62 in the inner circle of terminals, and extends therefrom radially outwardly of the disk 48 and then back toward the center of said disk. Each of said groups of a contact members also includes two fixed contact members iii and 82 which are supported on adjacent terminals 60 in the outer circle of terminals, and these contact members Sit and 32 are arranged to converge from the terminals on which they are supported toward one another andon opposite'sides of (that is, below and above, as shown in Fig. l) the U-shaped movable contact member '79 in that group. In the particular contact assembly illustrated, movable contact member 79 in each group is normally in electrical contact with upper fixed contact member 32 in that group; and flexing oicontact member 79 brakes its electrical connection with the upper contact 82 and completes its electrical engagement with lower contact 30.

As is obvious from Fig. l, the ends of the movable contact members 79 extend into the path of the flange of the actuator 42. When the actuator 42 is moved by the magnetic actuation of the armature 26 against the force exerted by'the spring '46, the edge of the flange id engages each of the movable contact members 79 and flexes those contact members to effect the breaking and completion of the electrical connections as above mentioned. Of, course, when the actuating coil of the relay is deenergized, the armature 26 and the actuator 42 return to their normal positions, and the movable contact members 79 return to their normal positions, as shown .in Fig. 1. As shown in Figs. 3 and 4, each of the U'shaped contact members 79, near its freeend, is provided with a longitudinally extending bulge 33, so

that it is shaped somewhatlike a pen nib, which serves to stiifen that portion of the contact member 79 and causes most of the flexing of it to take place at the bend, which is desirable. The annular groove in the face of flange 44 of actuator 42 causes the flange to engage the contacts 79 inwardly a short distance from their ends so that if there is a burr on the end it does not aifect the operation.

It will be noted that the arrangement of contacts is very compact. In the embodiment illustrated the relay contains six double-throw single pole switching units all operated simultaneously. Obviously the terminal-header may be designed to provide a difierent number of switching units.

As best shown in Fig. l, the various'parts of the relay are enclosed within a cup-shaped casing 84 which is provided at its top with an opening to accommodate the end 33 of the screw 32which initially projects from the end plate The casing 84 is slipped over the polepieces 12 and 14, and over the edge of the disk 48 of the terminal header. The edge of the casing 84 'is crimped over the edge of the disk 48 into'anotch provide'dtherein as shown. Thenotch isthen filled with solder which hermetically sealsone end of the unit. After the protruding end 33 of the screw 32 'hasbeen cut off, solder is applied at 40 to close the opening at that point in the casing 84. A ring 83 may be secured by welding or otherwise on the outside of the casing 34 and is provided with flanges 9% adapted to receive screws 92 for mounting.

Referring to Fig. 9, each contact is mechanically and electrically connected to its contact terminal by means of solder and a mounting sleeve which has a sliding fit on the terminal. The sleeve is shown in section at 9 l t has a hub portion 95 with a flat upper face and an initially cylindrical extension 96. A perforated contact such as 82 is slipped over this extension which is then riveted over as shown. The length of the sleeve, which is differcut for each of the three contacts of a set, determines the contact spacing. When the contacts have been aligned, solder is applied over the top 97 of terminal 60 and the surrounding parts of the sleeve and contact, fixing the position and forming a low resistance electrical union. The solder is shown at 98 in Figs. land 2.

It will be understood that-all; of the contacts are assembled on the terminals 60 and 62 in'the "disk48 of the terminal, header and adjusted to provide a subassembly. Since the contact members are directly mounted on the terminals 60 and 62, internal wiring to the contacts is completely eliminated.

It will be understood that the above described specific embodiment is merely illustrative of the invention, which is not limited to the foregoing details but is to be construed broadly in accordance with the appended claims.

What we claim is:

l. A terminal header and contact assembly for an electromagnetically operated switch comprising, a disc, contact terminals secured in and extending through said disc and insulated from one another, said terminals being arranged on spaced concentric circles, the number of terminals in the outer circle being double the number in the inner circle, groups of contact members mounted on said terminals, each of which groups consists of a U-shaped movable contact member secured at one end to a terminal on the inner circle and extending therefrom outwardly toward the edge of the disc and thence back toward the central portion of the disc, and two contact members sup ported onadjacent terminals on the outer circle and converging toward one another and extending on opposite sides of the'movable contact member of the group.

2. In an electromagnetic-ally operated switch, a terminal header assembly carrying a plurality of double-throw single-pole switching units; said units each comprising a movable middle contact in the form of a U-shaped spring anchored at one end to said header and having its free end pointing toward a central point, a pair of relatively fixed contacts anchored to said header at one end on either side of the loop in said middle contact and converging toward one another so that theirfree ends lie on opposite sides of said middlecontact; the free ends of the middle contacts of said units extending beyond the free ends of said fixed contacts; whereby the said free ends may all be engaged by a single actuating member moving in a direction' normal to the plane of said header between said fixed contacts.

3. A compact double-throw singl -pole contact assembly fora switch comprising, a support, three fixed terminals carried'thereby and arranged at the apices of a triangle, a U-shaped movable spring contact member secured at one end to one of said terminals with its looped end positioned between the other two terminals, and a pair of relatively fixed contacts secured at their ends to said other two terminals andconvcrging toward one another so that their free ends lie on opposite sides of said movable contact member, the free end of the movable contact member extending'beyond the ends oithe fixed contacts where it may be engaged by an actuator.

4. In an elcctromagnctically operated switch, a terminal header assembly carrying a plurality of switching units; said units each comprising a movable contact in the form of a U-shaped spring anchored at one end to said header and having its free end pointing toward a central point, a rclatively'fixed 'contact anchored to said header at one end 'at one side of the loop in said movable contact and having its other end lying on one side of the movable contact adjacent its free end; the free ends of the movable contacts of said units extending beyond the free ends of the movable contacts, whereby said free ends may all be engaged by a single actuating member moving in a direction normal to said header between said fixed contacts.

References 'Cited in the tile of this patent UNITED STATES PATENTS 783,652 Trcgoning Feb. 28, 1905 929,393 Corey July 27, 1909 1,031,312 Ziegler. .luly 2, i912 1,225,433 Gilmore May 8, 1917 1,317,203 Lynch Sept. 30, 1919 1,322,895 Gaylord Nov. 25, 1919 (Other references on following page) 5 UNITED STATES PATENTS Rah Nov. 24, 1931 Johnson Dec. 29, 1931 Hart June 29, 1937 Vigren et a1. May 2, 1939 o Gardiner Apr. 14, 1942 Dubilier June 2, 1942 Spahn, Jr. Feb. 13, 1945 Moorhead Aug. 7, 1945 10

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