US3198995A

US3198995A - Polarized electromagnetic relay

Info

Publication number: US3198995A
Application number: US143905A
Authority: US
Inventors: Alfred H Grebe
Original assignee: Allied Control Co Inc
Current assignee: Allied Control Co Inc
Priority date: 1961-10-09
Filing date: 1961-10-09
Publication date: 1965-08-03
Anticipated expiration: 1982-08-03

Description

A. H. GREBE Aug. 3, 1965 3 Sheets-Sheet 1 Filed Oct. 9. 1961 E m5 H m M m 3 W 4y B T; W wwv MW w x I y m Aug. 3, ,1965 A. H. GREBE 3,198,995

POLARIZED ELECTROMAGNETIC RELAY Filed 001:. 9, 1961 3 Sheets-Sheet 2 INVENTOR. 4/ ALF/P50 H GREBE BY J5 4 46 4439 Aug. 3, 1965 A. H. GREBE POLARIZED ELECTROMAGNETIC RELAY 3 Sheets-Sheet 3 Filed Oct. 9. 1961 INVENTOR. 41mm 6/8555 ATTOKA/EV United States Patent 3,198,995 POLARIZED ELECTROMAGNETIC RELAY Alfred H. Grebe, Cheshire, Conn., assignor to Allied Control Company, Inc, New York, N.Y., a corporation of New York Filed Oct. 9, 1961, Ser. No. 143,905 9 Claims. (Cl. 317-472) This invention relates to the art of electromagnetic devices and, more particularly, to a polarized relay having improved features of design and construction.

The relay of this invention has many and varied applications. It is especially useful in environments, such as on aircraft, which may be subjected to high inertia forces due to shock, vibrations and sudden acceleration and deceleration and in which space for operating equipment is limited. The relay may also be advantageously employed to operate various items of equipment including, but not limited to, one or more single pole or double pole switches, valves, flag indicators and the like. By way of example, the subject relay is illustrated and described further along herein in connection with a multi-pole double throw switch arrangement.

A preferred and recommended form of relay according to this invention comprises an electromagnet motor assembly which includes a horizontally disposed magnetizing coil, a core member which extends through the coil, and a pair of pole pieces which are secured to the ends of the core member and project above and below the coil. The lower portion of each pole piece is generally U- shaped and has a pair of spaced, laterally projecting end parts. A non-magnetic bridge unit is positioned under the coil and is secured to the pole pieces and to a support which is located below and in spaced relation to the coil. The bridge unit includes a top wall or deck, which spans the space between the pole pieces, and a plurality of spaced legs, which depend from the top wall and are afiixed to the support. The support is adapted to carry a plurality of switches, each of which has a pair of spaced stationary contacts and a movable contact arm which is adapted to engage a selected corresponding stationary contact.

A vertical shaft is secured to the top wall of the bridge unit and is disposed in the spaced between that wall and the support. The shaft is positioned midway between the pole pieces and carries a rotary armature having a pair of balanced arms. The armature comprises a permanent magnet, a bushing extending through the center of the permanent magnet for receiving the shaft, and a member of good magnetic material at each end of the permanent magnet and in intimate contact therewith. The armature is provided with a sheath. Each magnetic member includes end portions which project through the sheath and beyond the sides of corresponding and end portions of the permanent magnet. One end of each magnetic member faces a corresponding end part of one of the U-shaped portions of one pole piece and the other end of each magnetic member faces a corresponding end portion of the U-shaped portion of the other pole iece.

p A tubular actuator, which is made of an electric insulating material and is coaxial with the shaft, is attached to and rotatable with the armature. The actuator is provided with a plurality of circumferentially spaced slots that receive corresponding movable contact arms of the switches. Portions of the actuator which define the slots are adapted to actuate all of the movable contact arms simultaneously in response to predetermined rotary movement of the armature in either direction.

When the foregoing parts are assembled, they are placed in an upstanding tubular housing which is closed at the top and open at the bottom. The upper ends of the pole pieces register with openings in the top of the housing and are anchored thereto. The support is positioned in and sealed to the open bottom of the housing.

The design, relationship and characteristics of the armature and the pole pieces are such that, with the coil deenergized, the armature is held in the extreme angular position relative to the pole pieces, to which it had last been actuated, due to the permanent magnet flux; and the movable contact arms are flexed by the actuator so as to engage corresponding stationary contacts. Upon upper energization of the coil, there is created electromagnetic flux which opposes the permanent magnet flux in the closed armature gap and aids the permanent magnet flux in the open armature gap. A condition of mechanical force and flux force imbalance occurs which causes rotary movement of the armature to its other extreme angular position relative to the pole pieces and flexing of the movable contact arms to effect their disengagement from the indicated stationary contacts and engagements with corresponding other stationary contacts. The parts remain in this position until such time as the coil is energized in a reverse direction, thereby causing reverse operation of the armature and associated parts.

The present relay embodies a number of Worthwhile features which facilitates manufacture and contribute to its durability and utility. Such features include the following:

(1) The electromagnet unit of the relay includes a core bushing and a core which are so designed as to permit substantial assembly of that unit before applying the coil.

(2) The armature is a unitary cast assembly comprising a permanent magnet, a central bushing and a magnetic member at each end of the permanent magnet and extending beyond its sides.

(3) The electromagnet unit is fully adjustable for electromagnetic flip-flop operation prior to affixing the header assembly. This is accomplished by charging the magnet, applying alternate polarities to the coil and adjusting the pole face alignments until the flip voltage is of equal but opposite polarity to the flop voltage. Also, the permanent magnet can be readily charged and discharged to facilitate cleaning out foreign particles.

(4) By constructing the armature so that the ends of the permanent magnet are readily accessible for charging and discharging, the operating sensitivity of the relay is easily adjusted within maximum and minimum limits, the maximum operating voltage being determined by the maximum flux of the permanent magnet and the minimum operating voltage being determined by the minimum holding force of the permanent magnet.

(5) By anchoring the upper ends of the pole pieces to the top of the housing, the relay assembly is attached more firmly to the housing than otherwise. This reduces fatigue failure due to vibrations over extended periods of time.

(6) The legs of the bridge units are strengthened laterally by integral straps or arms which are secured to the pole pieces.

(7) The various switch contacts are in full view for inspection, adjustment and cleaning before the relay assembly is inserted in its housing.

(8) The movable contact arms are captured in corresponding actuator slots. This eliminates the need for self-biasing for normally closed contact pressures and provides positive contact pressures for withstanding shocks and vibrations. This also substantially reduces the possibility of contact bounce during use.

The primary object of this invention is to provide a polarized relay that is capable of being made in a small size and that is adapted to withstand shock forces, vibra- U tions, and sudden acceleration or deceleration during normal use.

Another object of the invention is to provide a polarized relay of improved design and construction, including a rotary armature which is adapted to operate a plurality of devices, such as movable contact arms, substantially simultaneously.

A further object of the invention is to provide a relay of the type indicated that is small and lightweight in design, that is strong and durable in construction, that is reasonable in manufacturing cost and that is capable of performing its intended functions in a satisfactory and dependable manner.

The enumerated objects and additional objects, together with the advantages of the invention, will be readily understood by persons trained in the art from the following detailed description and the accompanying drawings which described and illustrate, by way of example, a six pole double throw relay according to the invention.

in the drawings, wherein like reference characters identify like parts in the several views:

PEG. 1 is a bottom plan View of the relay;

FIG. 2 is an elevation view of the relay shown in FIG. 1;

FIG. 3 is a view in enlargement taken along line 3-3 of Pro. 1;

FIG. 4 is a view taken along line 4-4 of FIG. 3;

FIG. 5 is a view taken along line 5-5 of FIG. 4;

FIG. 6 is a view in enlargement taken along line 66 of FIG. 3;

FIG. 7 is a fragmentary view taken along line 77 of FIG. 6;

FIG. 8 is a top plan view of the armature in enlargement partly broken away and partly in cross section for better illustration;

FIG. 9 is a view taken along line 9-9 of FIG. 8; and

FIG. 10 is a schematic representation of the electromagnet unit of the relay and illustrates the armature and pole pieces in a relative position corresponding to that shown in FIG. 5.

The complete relay, as best shown in FIGS. 1, 2 and 3, includes a tubular casing or housing 10 which comprises a cylindrical side wall 11 and a top wall 12 having a pair of openings 13. The housing is open at its lower end and is provided with a mounting ring 14 which is secured to side wall 11. The mounting ring has a pair of diametrically opposed openings 15 to receive attaching screws or the like (not shown).

An electromagnet motor unit is generally denoted by numeral 16 and includes a bobbin 17 on which there is wound a magnetizin coil C that is provided with three insulating leads, consisting of a pair of leads 18 and a third lead 19, only one of leads 1% being visible in the drawings. The coil is sheathed in a protective outer wrapper 20. A core bushing 21, which is made of a good magnetic material, is positioned in and is co-extensive with the hub of the bobbin. The electromagnet unit also includes a pair of parallel pole pieces P and P which are arranged at opposite ends of the bobbin and are afiixed thereto by a core member 22 that extends through the pole pieces and the bushing. The core member is made from a right circular cylindrical bar of a good magnetic material and is provided at one end with a head 23 which bears against the outer surface of pole piece P. The other end of the core member extends through pole piece P and is peened over, as indicated at 24 (FIGS. 3 and 4).

Pole pieces P has an inverted, generally T-shape and is formed at its upper end with an extension 25 which registers with an opening 13 in housing top wall 12. The lower end portion of this pole piece is generally U-shaped, as illustrated in FIG. 5, and includes a pair of lateral wings or end

parts

26 and 27. The pole pieces are preferably identical. The parts of pole piece P which are the same as those of pole piece P are identified by corresponding primed numerals in the drawings.

Secured to the pole pieces and projecting downwardly therefrom is a one-piece, non-magnetic bridge unit B. Th bridge unit comprises a top wall or deck 34), which is positioned between the pole pieces and bears against the upper edges of the U-shaped portions of the pole pieces; and a plurality of, namely four, spaced depending legs 31, each having an extension 32 at its lower end. Integral with deck are

upstanding tabs

33 and 34 which are disposed along and afilxed to corresponding edge portions of the pole pieces, preferably by spot welding. integral with each leg 31 is a bent lateral tab or strap 35 which bears against an adjacent part of a corresponding pole piece and is secured thereto, preferably by spot Welding, as indicated at 36 in FIG. 4.

A shaft 37 extends through a central opening (not shown) in bridge deck 34 and is eened over, as indicated at 38, to obtain a firm connection between these parts. The shaft is normal to the axis of the magnetizing coil and is located midway between the U-shaped portions of the pole pieces. An annular groove 39 is provided in the lower portion of the shaft (FIG. 9).

Reference is next had to the FIGS. 8 and 9 for an understanding of the details of construction of an armature A which is rotatable about the axis of shaft 37. The armature comprises a permanent magnet 49 which has a central opening (not identified in the drawings) and which is ensheathed in a casing 41 that is open at its ends. The armature also comprises a pair of

bar members

42 and 43 which are made of a good magnetic material, such as soft iron. The bar members bear against and form intimate contact with corresponding ends of the permanent magnet. The end portions of the bar members extend through and beyond casing 41. A bushing 44 is disposed in a central opening through the casing and the permanent magnet and serves as a bearing member for the armature and shaft assembly. The armature is relcasably maintained on the shaft by a low-friction split ring 45 which registers with groove 39. Casing 41 is formed with a plurality of depending, angularly spaced teats 46.

The armature carries a contact actuator which is made of a suitable electric insulating material, such as an appropriate synthetic plastic composition. The actuator consists of a top wall 51 (FIG. 5) and a depending tubular side wall 52. Top wall 51 is provided with a central opening 53 to receive bushing 44 and a plurality of spaced openings 54 to receive and retain teats 46 which are peened over, as illustrated in FIG. 9. Side wall 52 is provided with six equi-spaced slots 55 which extend upwardly from its lower edge. It will be observed that actuator 59 is rotatable with armature A about the axis of shaft 37.

FIGS. 3, 6 and 7 illustrate details of construction of a header assembly H which is secured to bridge B and is positioned below and in spaced relation to armature A. The header assembly includes a circular support plate 56 which is provided with a plurality of peripheral slots 57 to receive bridge leg extensions 32 (FIG. 3). These extensions are secured to the support plate by spot welding or in any other desired manner known to the art. The support plate carries a number of parts comprising electrical connections, switch contacts, and other elements that will now be identified and described. Such parts include six pairs of fixed

terminals

60 and 61 which are spaced equidi-stantly from each other and are arranged about an outer circumference; six fixed terminals 62 which are spaced about an inner circumference; a pair of fixed terminals 63 and a central fixed terminal 64. All terminals extend through support plate 56 and are anchored thereto by corresponding masses of a suitable, rigid, insulating material, such as glass (FIG. 7). Each terminal 63 is connected to a corresponding coil lead 18, while terminal 64 is connected to coil lead 19. Terminals 63 and 64 are adapted to be connected to a suitable source of electric energy supply. Atllxed to

terminals

60 and 61, preferably by welding, are corresponding L- shaped

stationary contacts

60a and 61a.

An electrically conductive leaf spring contact arm 66 is provided for each pair of contacts 69a and 61a. Each contact arm is anchored proximate one end to a corresponding terminal 62 and is equipped at its other end with a double button contact 67 which is positioned between corresponding stationary contacts 6t1a and 61a. Each contact arm registers with a corresponding slot 55 in actuator 50. The parts are so constructed and arranged that all contact arms 66 are adapted to be flexed simultaneously relative to their terminals 62 in response to predetermined increments of rotary movement of the armature and the actuator in either direction. This eifects engagement of each button contact 67 with its

stationary contact

60a or 61a, depending on the position of the armature. FIG. 6 shows the button contacts in engagement with stationary contacts 66a as a result of previous rotary movement of the actuator in a clockwise direction.

In the schematic representation of the electromagnet unit shown in FIG. 10, permanent magnet 40 is designated as having a north pole N and a south pole S. Also, the armature is shown at its extreme counterclockwise pivoted position relative to the pole pieces, magnetic member 43 being in contact with part 27 of pole piece P and out of contact with part 27' of pole piece P and magnetic member 42 being in contact with part 26' of pole piece P and out of contact with part 26 of pole piece P. The parts are held in this position by the permanent magnet flux which permeates from north pole N, through the upper end of member 43 to part 27, through pole piece P, core 22, pole piece P, part 26', member 42 and thence to south pole S of the permanent magnet.

For the purpose of outlining the operation of the above-described form of the invention, it is assumed that the relay is assembled and that the parts are in relative position shown in FIGS. 3, 5, 6 and 10. It is also assumed that magnetizing coil C is de-energized. The coil is now energized in a direction to make

parts

27 and 26 electromagnetic north poles and parts 26 and 27' electromagnetic south poles. The created electromagnetic flux will permeate from part 27 to member 43, to part 27' and thence through pole piece P, core 22 and pole piece P to part 27. At the same time electromagnetic flux permeates from part 26 to member 42, to part 26' and thence through pole piece P, core 22 and pole piece P to part 26. This results in an imbalance of forces, namely that due to the permanent magnet flux and that due to the electromagnetic flux, such as to cause pivotal movement of armature A in a clockwise direction, as viewed in FIG. 10, moving member 43 out of contact with part 27 and into contact with part 27 and simultaneously moving member 42 out of contact with part 26' and into contact with part 26. Upon deenergization of the coil, the parts are retained in such position. It will be apparent that the indicated clockwise rotation of the armature will cause the actuator to also rotate in a clockwise direction, as viewed in FIG. 6, and ope-rate movable contact arms 66 so that all button contacts 67 are simultaneously moved from stationary contacts 60a to corresponding stationary contacts 61:: (FIG. 6).

By reversing the direction of the energizing current through the coil, the above-outlined operational procedure will be reversed and the parts will return to the relative position shown in the drawings.

A further contribution to the imbalance of forces may be introduced by the movable contact arms being made of spring-like material which resists motion from a neutral position between fixed

terminals

60 and 61.

It will be appreciated by persons trained in the art that the relay of this invention may be readily altered by minor modifications to obtain a center-01f or neutral position of the armature. This may be accomplished by (1) maintaining the permanent magnet strength but providing non-magnetic shims on the pole pieces to facilitate unlatching in terms of voltage or (2) reducing the permanent magnet strength and providing anti-freeze shims on the armature or pole pieces so that the relay will function as a momentary type switch which requires voltage to hold the relay in either of the two energized positions.

From the foregoing, it is believed that the objects, advantages, construction and operation of my present invention will be readily comprehended by persons skilled in the art without further description. Although the invention has been herein shown and described in a simple and practicable form, it is recognized that certain parts thereof are representative of other parts which may be used in substantially the same manner to accomplish sub stantially the same results. Therefore, it is to be understood that the invention is not to be limited to the exact details described herein, but is to be accorded the full scope and protection of the appended claims.

I claim:

1. A polarized relay comprising a magnetizing coil, a core member extending through the coil, a pair of spaced pole pieces secured to the core member, each pole piece including a generally U-shaped portion having a pair of spaced end parts, a non-magnetic unit secured to the pole pieces, and extending across the space between the pole pieces, an armature carried by the non-magnetic unit and pivotal about an axis which is normal to and intersects the axis of the coil, said armature being positioned between the U-shaped portions of the pole pieces and including a permanent magnet and a magnetic member at each end of the permanent magnet and in intimate contact therewith, one end of each magnetic member facing a corresponding end part of the U-shaped portion of one pole piece, the other end of each magnetic member facing a corresponding end part of the U-shaped portion of the other pole piece.

2. A polarized relay comprising a horizontally disposed magnetizing coil, a core member extending through the coil, a pair of spaced pole pieces secured to the core member, a support positioned below the coil, a non-magnetic bridge unit connected to the pole pieces and to the support and maintaining the coil in spaced relation to the support, an armature carried by the bridge unit in the space between the coil and the support and pivotal about a vertical axis which intersects the axis of the coil, said armature being positioned between the pole pieces and including a permanent magnet having a pair of free end par-ts which are disposed to opposite sides of said vertical axis and a magnetic member at each free end part of the permanent magnet and in intimate contact therewith, each magnetic member including end portions which project beyond the sides of corresponding free end parts of the permanent magnet.

3. A relay according to claim 2 wherein one end of each magnetic member faces a corresponding pole piece.

4. A polarized relay comprising a horizontally disposed magnetizing coil, a core member extending through the coil, a pair of spaced pole pieces secured to the core member, each pole piece including a generally U-shaped portion positioned below the coil and having a pair of spaced end parts, a support positioned below the coil, a non-magnetic bridge unit connected to the pole pieces and to the support and maintaining the coil in spaced relation to the support, an armature carried by the bridge unit in the space between the coil and the support and pivotal about a vertical axis which intersects the axis of the coil, said armature being positioned between the U-shaped portions of the pole pieces and including a permanent magnet and a magnetic member at each end of the permanent magnet and in intimate contact therewith, one end of each magnetic member facing a corresponding end part of the U-shaped portion of one pole piece, the other end of each magnet member a s r sneasee facing a corresponding end part of the U-shaped portion of the other pole piece.

5. A polarized relay comprising a horizontally disposed magnetizing coil, a core member extending through the coil, a pair of spaced pole pieces secured to the core member, each pole piece including a generally U-shaped portion positioned below the coil and having a pair of spaced end parts, a support positioned below the coil, a non-magnetic bridge unit connected to the pole pieces and to the support and maintaining the coil in spaced relation to the support, an armature carried by the bridge unit in the space between the coil and the support and pivotal about a vertical axis which intersects the axis of the coil, said armature being positioned between the U-shaped portion of the pole pieces and including a permanet magnet and a magnetic member at each end of the permanent magnet and in intimate contact therewith, each magnetic member including end portions which project beyond the sides of corresponding end portions of the permanent magnet, one end of each magnet member facing a corresponding end part of the U-shaped portion of one pole piece, the other end of each magnet member facing a corresponding end part of the U-shaped portion of the other pole piece.

6. A polarized relay comprising a horizontally disposed magnetizing coil, a core member extending through the coil, a pair of spaced pole pieces secured to the core men ber, each pole piece including a generally U-shaped portion positioned below the coil and having a pair of spaced end parts, a support positioned below the coil, a nonmagnetic bridge unit connected to the pole pieces and to the support and maintaining the coil in spaced relation to the support, said bridge unit comprising a top member beneath the coil and spaced from the support and a plurality of spaced legs extending from the top member to the support, a vertical shaft connected to the top member projecting into the space between the top member and the support, an armature carried by and rotatable about the shaft, said armature being positioned between the U- shaped portions of the pole pieces and including a permanent magnet and a magnetic member at each end of the permanent magnet and in intimate contact therewith, one end of each magnetic member facing a corresponding end part of the U-shaped portion of one pole piece, the other end of each magnetic member facing a correspond ing end part of the U-shaped portion of the other pole piece.

7. A polarized relay comprising a horizontally disposed magnetizing coil, a core member extending through the coil, a pair of spaced pole pieces secured to the core member, each pole piece including a generally U-shaped portion positioned below the coil and having a pair of spaced end parts, a support positioned below the coil, a nonmagnetic bridge unit connected to the pole pieces and to the support and maintaining the coil in spaced relation to the support, said bridge unit comprising a top member beneath the coil and spaced from the support and a plurality of spaced legs extending from the top member to the support, a vertical shaft connected to the top member and projecting into the space between the top member and the support, an armature carried by and rotatable about the shaft, said armature being positioned between the U- shaped portions of the pole pieces and including a perma nent magnet and a magnetic member at each end of the permanent magnet and in intimate contact therewith, each magnetic member including end portions which project beyond the sides of corresponding end portions of the permanent magnet, one end of each magnetic member facing a corresponding end part of the U-shaped portion of one pole piece, the other end of each magnetic member facing a corresponding end part of the U-shaped portion of the other pole piece.

3. A relay according to claim 7 wherein the shaft is midway between the pole pieces and the armature is so formed as to obtain a pair of balanced arms which extend to opposite sides of the axis of the shaft.

9. A relay according to claim 7 including an actuator affixed to and rotatable with the armature, said actuator being adapted to operate a means, which is adapted to be mounted on the support, in response to predetermined rotary movement of the armature in at least one direction.

References Cited by the Examiner UNTTED STATES PATENTS 2,941,130 6/60 Fischer et al 31717l 3,017,474 1/62 Huetten 3l717l 3,041,422 6/62 Greshel 200-93 3,097,328 7/63 Sauer 317-199 LARAMIE E. ASKIN, Primary Examiner.

JOHN F. BURNS. Examiner.

Claims

1. A POLARIZED RELAY COMPRISING A MAGNETIZING COIL, A CORE MEMBER EXTENDING THROUGH THE COIL, A PAIR OF SPACED POLE PIECES SECURED TO THE CORE NUMBER, EACH POLE PIECE INCLUDING A GENERALLY U-SHAPED PORTION HAVING A PAIR OF SPACED END PARTS, A NON-MAGNETIC UNIT SECURED TO THE POLE PIECES, AND EXTENDING ACROSS THE SPACE BETWEEN THE POLE PIECES, AN ARMATURE CARRIED BY THE NON-MAGNETIC UNIT AND PIVOTAL ABOUT AN AXIS WHICH IS NORMAL TO AND INTERSECTS THE AXIS OF THE COIL, SAID ARMATURE BEING POSITIONED BETWEEN THE U-SHAPED PORTIONS OF THE POLE PIECES AND INCLUDING A PERMANENT MAGNET AND A MAGNETIC MEM-