US1925997A - Relay - Google Patents

Description

Sept. 5, 1933. J w BA 1,925,997

RELAY Filed May 18, 1932 IFE'TTIEF J1: se 'h In]. E arkham Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE RELAY of Delaware Application May 18, 1932.

18 Claims.

This invention relates in general to electromagnetic relays of the type adaptable for use in telephone practice or other places where relatively small values of current are used for op- 5 crating the relays, and the principal object of the invention is the provision of an electromagnetic relay in which the operation is extremely efiicient, which has a strong magnetic circuit for operating larger spring loads, is simply and easily adjusted, and is more sensitive and reliable in operation than electromagnetic relays have been heretofore.

It is a. further object of the invention to provide a relay having a magnetic circuit with only a single air gap in it thereby providing a low reluctance magnetic circuit path.

A further object resides in providing an electromagnetic relay in which the leakage flux between the core of the relay and the heel piece is reduced to a minimum.

In accordance with the above objects a number of features are contained in the electro magnetic relay of the invention, such as, a core and a heel piece which are placed edgea wise to each other so as to present narrow opposing surfaces and thereby considerably reduce the leakage of the magnetic flux flowing across the core and heel piece when the magnet coil is energized; a large bearing pin on the heel piece for the armature so that the air gap between the armature and the heel piece is practically eliminated and at the same time provide a longer operating life for the moving part of the armature; and anadjustment of the heel piece with respect to the core so that the armature may be properly positioned opposite the end of the core and operate correctly in the desired manner.

The invention is illustrated in the accompanying sheet of drawing which, together with the description discloses a preferred embodiment of the invention. In the drawing, Fig. 1 shows a side elevation of an electromagnetic relay according to the invention; Fig. 2 is a view of the same relay as seen from the bottom; Fig. 3 is a rear View of the relay; while Fig. 4 is a top View of the armature end of the relay. Fig. 5 is a side elevation of a modification of the electromagnetic relay; and Fig. 6 is a top view from the armature end of the modified form of relay.

Referring now more particularly to Fig. 1 the relay comprises the usual coil winding 1 wound on a spool which fits over the flat metal core r 2 having a turned over end 3 at the armature end. A pair of mounting screws 4 secure one end of Serial No. 612,058

the core 2 to the flat metal heel piece 5. The heel piece is arranged parallel to the flat surface of the core 2 so that both present their narrow opposing edges to each other as is more clearly seen in the top view, Fig. 4. A portion 6 of the heel piece 5 is turned up and provides a means for suitably supporting the electromagnetic relay as a whole on a mounting frame. Another projection 7 of the heel piece 5 is turned up and arranged to serve as a mounting plate for a number of flexible contact springs 8 only a few being shown, and which are secured by means of the pair of screws 9 in the projecting portion '7. A non-magnetic armature backstop 36 is also held in place on the projection 7 by the screws 9. From the foregoing it will be seen that the heel piece member 5 can be stamped and formed of a single piece of flat metal provided with the projecting portions 6 and '7, resulting in a very economical arrangement.

A flat magnetic armature 15, the general shape of which is more clearly seen in Fig. 4, is pivoted to one end of the heel piece 5 by means of a pair of projecting portions 17 and 18 extending from opposite sides and integral with the armature 15. The armature 1-5 is formed at its supporting end into a curved or semi-circular shape 16 more clearly seen in Figs. 1 and 3. A brass hearing pin 20 extends through the projecting pieces 17 and 18 and the heel piece 5 to -form a pivot point for the armature 15. The projecting piece 18 has an armature lever 19 formed integral with it and suitably cent so that it can engage the contact springs 8 to operate the same when the armature is actuated. A cylindrical shaped iron pin 21 is riveted at one end to the heel piece 5 directly below the semi-circular portion 16 of the armature 15. The crass bearing pin 20 extends through this iron pin and the arrangement is such that armature 15 in its operation rotates its semi-circular portion 16 about the metal pin 21 but without engaging it at any point so that at all times a minimum amount of air space for the magnetic flux to cross extends between these two members.

In most prior electromagnetic relays the struc ture usually comprised. a core of round or cylindrical shape and a flat heel piece which together with the armature completed the magnetic circuit. The heel piece is usually arranged so that one end of it is fastened to one end of the round core while the armature is pivoted on the other end and it has its widest surface arranged parallel to and adjacent the core of the relay. When the coil is energized a magnetic flux is created which extends over a magnetic circuit path including the core, heel piece, and the armature in order to operate the same. With this arangement of parts, however, considerable flux leakage takes place between the core and the wide surface of the heel piece, because the large surfaces between the two and their proximity presents a comparatively low reluctance path for the flux to leak across. This leakage consequently reduces the amount of fiux flowing through the armature and the core and considerably reduces the pull upon the armature. By providing a fiat core and a flat heel piece in which the widest edge is parallel with the fiat surface of the core and in which the narrow edges of the core and heel piece are adjacent to one another according to the invention a smaller opposing surface is presented between the two so that the flux leakage is very small and a relatively high reluctance magnetic path exists between them. As a result practically all of the flux flows from the core through the heel piece to the armature without any great loss, rendering the pull upon the armature very strong and powerful and the operation of the relay more eflicient, permitting the operation of greater contact spring loads than has been heretofore possible.

A further reason for the great efiiciency of the magnetic circuit of the relay described, resides in the pivoting arrangement of the armature. In former types of electromagnetic relays the armature was usually pivoted on the heel piece between two projecting ear members on the heel piece through which a brass pivoting pin projected and engaged other ear members on the armature. This arrangement, it is seen, introduced a considerable air gap and high reluctance magnetic path over which the magnetic circuit was completed and thereby reduced the magnetic pull upon the armature even though the other parts of the magnetic circuit path, including the heel piece and the core, were as efliciently constructed as possible. The invention overcomes this diificulty by providing a cylindrical iron pin 21 fastened to the heel piece 5 and an armature 15 which is provided with a semicircular portion 1.6 snugly fitting over a portion of the surface of the pin 21 and pivoted to heel piece 5 by the brass pin 20. A small space is provided between the pin 21 and the bottom surface of the circular portion 16 of the armature 15 so that they do not frictionally engage. With this arrangement a large area or surface is presented in the magnetic circuit path so that the magnetic flux flowing from the core 5 extends over the whole surface of the pin 21 across the minute air gap between the pin and the circular portion 16 of the armature which has a large surface opposing practically half of that of the roller 21, and a very low reluctance mag netic path, therefore, exists so that the pull upon the armature 15 is very powerful against the core 3.

When the relay after having been operated deenergizes, the armature 15 is restored to normal due to the pressure of the operated contact springs 8 upon the end of the armature lever 19. This pressure overcomes any tendency of the armature 15 to stick against the bent over end 3 of the core 2 due to residual magnetism which may exist in the decaying magnetic circuit. If desired a small brass shim may be inserted over the bent over portion 3 of the core 2 as is the usual practice.

In order to provide a ready means for adjusting the stroke of the armature 15 against the bent over portion 3 of the core 2 and in order to adjust it so that it lies flat against the core piece 3 when fully attracted, an arrangement is provided according to the invention for conveniently doing this. One of the mounting screws 4 which secure the heel piece 5 directly on one end of the core 2, rides in a slot 25 in the heel piece so that by merely loosening the screws 4 and rotating the heel piece 5 about a pivot point formed by the right hand one of the mounting screws 4, the heel piece 5 may be slightly rotated closer or farther away from the armature end of the core 2 until the proper adjustment of the armature 15 with respect to the core portion 3 is obtained. When this is done both screws 4 are tightened.

To avoid friction and also magnetic attraction or sticking of the ear members 1'7 and 18 of the armature 15 against the pin 21 and heel piece 5, a small brass washer is inserted on the pivoting pin 20 adjacent the ear members as shown.

In Figs. 5 and 6 a modification of the invention is disclosed. The coil 1, core 2, and bent over portion 3 of the core 2, together with the heel piece 5, extension 6 for mounting the relay and the extension 7 for supporting the set of contact springs 8, are all of the same construction as Fig. 1. A slightly different armature adjustment, however, is provided in that the screws 4 for supporting the core 2 on the heel piece 5 engage slotted holes 25 so that the core 2 may be moved closer or farther away from the armature 15 in order to position it properly on the extended turned over portion 3 of the core.

In the modification shown in Fig. 1 the semicircular portion 16 of the armature 15 only partially encircles the iron pin 21 attached to the heel piece 5, but in the modification shown in Fig. 5, however, the armature 15 is formed with a cylindrical iron tube 34 on its rear end. An iron bearing pin 30 fits inside of the tube 34 of the armature and serves as a bearing for the same. This bearing pin 30 is immovably and rigidly attached to the heel piece 5 by means of a screw 31 which threads into the end of the pin 30. An iron washer 32 fits under the screw 31, while brass washer 33 fits between the end of the tube portion 34 and the heel piece 5 in order to prevent the armature from sticking to the heel piece when the magnetic circuit is completed. The armature lever 19 is securely attached as by riveting to the end of the tube 34 of armature 15 and is keyed to it as shown so that it does not turn relative to the armature. Due to the fact that the tube portion 34 of the armature 15 completely surrounds the iron bearing pin 30 the air gap usually adjacent these two surfaces is practically eliminated as a large surface between them is always in direct contact with the bearing pin. When the flux flows the reluctance of the magnetic circuit at this point is very low and the full flow traverses the magnetic circuit without any loss. As seen by the dotted lines in Fig. 5 the armature bearing pin 30 carrying the armature 15 is adjustable lengthwise of the heel piece 5 by merely loosening the screw 31 and sliding it up or down in the slot 35 in the heel piece and then tightening the same again. This moves the armature 15 closer or farther away from the turned over portion 3 of the heel piece 2 and provides an adjustment in addition to that provided by the mounting screws 4 sliding in slots 25 in the core 2.

It will be understood that while the armatures in each of the modifications have been shown as pivoted to the side of the heel piece 5 it will be appreciated that the construction contemplates an arrangement in which the armature may be pivoted on opposite sides of the heel piece 5; that is, a slot may be cut in the armature and the heel piece accommodated therein. This would place the core 2 and heel piece 5 directly opposite and parallel to one another instead of to one side as shown in the drawing.

What is claimed is:

1. In an electromagnetic device, the combination of a fiat core and heel piece, respectively, set edgewise with respect to each other together with means for adjusting them relative to each other.

2. In an electromagnetic device, the combination of a flat core and heel piece in which the narrow edges are adjacent one another so as to reduce the flux leakage between them together with means for supporting said core on said heel piece in an adjustable manner.

3. In an electromagnetic device, the combination of a core and a heel piece in which each is constructed with wide edges and narrow edges and in which one of the narrow edges of each is placed adjacent one of the narrow edges of the other and means for adjustably supporting the core on the heel piece.

4. In an electromagnetic device, the combination of a core and heel piece each having wide and narrow edges and in which only their narrow edges are adjacent one another and in which the core is supported on the heel piece, together with means for varying the separation between them.

5. In an electromagnetic device, the combination of a flat core and a flat heel piece arranged with the flat sides in approximately the same plane so as to reduce to a minimum the leakage of flux between them, an armature mounted on said heel piece, and means for adjustably supporting said core on said heel piece so the position of the armature with respect to the core may be varied.

one end of the core for rotatably supporting the heel piece thereon so as to move the heel piece closer or farther away from the armature end of the core and thereby adjust the position of the armature with respect to the core.

8. In an electromagnetic device, a core, a heel piece having an armature pivoted opposite one end of said core, said heel piece rotatably supported on the other end of said core so that the position of the armature with respect to the core may be varied.

9. In an electromagnetic device, a flat core, a flat heel piece having an armature pivoted opposite one end of said core, said heel piece arranged with the flat side substantially paralel to the flat side of said core and rotatably supported on one end thereof so as to move the armature end of the heel piece closer or farther away from the core and thereby vary the position of the armature with respect to the core, and means for holding said heel piece in its adjusted position.

10. In an electromagnetic device, a core, a heel piece secured to one end of said core, an armature on said heel piece opposite the other end of said core, a magnetic pin secured to said heel piece for pivoting the armature opposite the end of the core, said armature having a portion enclosing but not in engagement with said pin to present a large surface for the flow of magnetic flux between said pin and armature.

11. In an armature pivoting arrangement, a heel piece, a magnetic pin secured to said heel piece, an armature pivoted only at the ends of said pin, and an extended portion on said armature conforming to the shape of and rotatable about said pin but not in engagement therewith.

12. In an armature pivoting arrangement, a heel piece, a magnetic pin secured to said heel piece, an armature pivoted to said magnetic pin, and a curved extension on said armature rotatable about said pin when said armature is moved but without engaging it at any point.

13. In an armature pivoting arrangement, a heel piece, a circular pin secured to said heel piece, an armature pivoted only at the ends of said circular pin, and a curved extension on said armature conforming to the shape of and rotatable about said circular pin without engaging the same at any point.

14. In an armature pivoting arrangement, a heel piece, a circular bearing pin mounted on said heel piece, an armature pivoted to said bearing pin, and a semi-circular portion on said armature partially encircling said bearing pin and rotatable thereabout when said armature is operated without coming into contact with it at any point.

15. In an armature pivoting arrangement, a 115 heel piece, a magnetic bearing pin secured to said heel piece, and an armature provided with an opening through which said bearing pin extends so that said bearing pin is completely surrounded by said armature.

16. In an armature pivoting arrangement, a heel piece, a bearing pin secured to said heel piece, an armature provided with an enlarged portion having an opening therein through which said bearing pin extends, said enlarged portion 125 of the armature completely surrounding said bearing pin and engaging it at all points.

17. In an armature pivoting arrangement, a heel piece, a bearing pin rigidly secured to said heel piece, an armature, an enlarged circular 130 bearing portion on said armature through which said bearing pin extends so that it engages with it over its whole surface when the armature is operated, and means for adjusting the position of said bearing pin on said heel piece.

18. In an armature pivoting arrangement, a heel piece, an armature having a circular por tion provided with an opening, a magnetic bearing pin secured to said heel piece and extending through the opening of said circular portion of the armature to serve as a pivot for the same, said bearing pin and circular portion presenting large surfaces in contact with each other, and a non-magnetic washer between said heel piece and the end of said circular portion to prevent .I'c' the armature from sticking to the heel piece due to residual magnetism.

JOSEPH W. BARKHAM.

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