US3043932A - Polarized relay - Google Patents

Description

July 10, 1962 G. v. MORRIS 3,043,932

POLARIZED RELAY Filed March 30, 1959 EG. .Z

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ATTO EY July 10, 1962 G. v- MORRIS 3,043,932

POLARIZED RELAY Filed March 3o, 1959 2 sheds-sheet 2 'marient magnet.

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United States Patent i 3,043,932 PoLARIzED RELAY 'George V. Morris, Chicago, Ill., assigner to Zenith Radio This invention relates to polarized relays and is directed, among yother things, to their magnetic structures and to their use in remote control systems.

One type of polarized relay well known in the art for performing switch functions employs a pair of magnetic `structures for establishing respective magnetic tlux elds. VOne of the fields is Supplied by an electromagnetic arrangement having a movable armature and a coil which upon energization polarizes the armature so that it serves as a magnetic pole. A coacting ux iield is supplied by thetsecond magnetic structure which comprises a pair of pole pieces, spaced to define an air gap, and a per- One end of the movable armature is centered in 4the air gap `so that upon energization of the coil, the magnetic pole induced in that end of the armature drives the armature toward the oppositely polarized pole piece of the permanent magnet structure to complete a switch operation.

Proper operation of a polarized relay requires that the flux established across the air gap -by the permanent magnet structure be maintained uniform, otherwise coil energizing currents of substantially equal magnitude but of opposite polarity supplied to the electromagnetic arrangement do not produce complementary displacements of the armature. To insure a uniform magnetic flux across the air gap, leakage flux from the permanent magnet must be minimized. This leakage is determined to a large extent, by the mounting of the permanent magnet with 'respect to its associated pole pieces and is aggravated when a common mounting assembly is employed for the arrangement.v

It is therefore an object of the invention to provide a polarized relay employing an improved magnetic structure arrangement which minimizes the eifect of magnetic vflux leakage.

It is also an object of the invention to provide a polarized relay utilizing a novel magnetic structure for establishing a substantially uniform magnetic iux.

It is a further and specific object of the invention to provide an improved polarized relay especially adapted yfor use in remote control systems.

A polarized relay constructed in accordance with the invention comprises aV magnetic motor constituted by a magnetic structure that has at least one energizing coil for establishing magnetic flux in the structure having a polarity determined by the polarity Iof the energizing cur- A resilient armature included in the structurehas a free end which serves as a magnetic pole and is polarized in accordanec with the polarity of the established magnetic flux. The relay further includes a second magnetic structure having a principal air gap deiined by a pair of space opposed elongated pole pieces. A pair of magnets carried at opposed ends of the pole pieces, respectively, are positioned transversely of the air gap and at opposed ends thereof to define respective compensating air gaps for neutralizing leakage ux thereby establishing a substantially uniform magnetic iiux across the principal gap. Means are also provided for positioning the magnetic motor adjacent the second magnetic structure so that the free end of the armature is symmetrically disposed in the principal air gap.

The features of this invention which are believed to be v o 3,043,932 Patented July 10, 1962 novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood, however, by reference to the following description taken in conjunction with the accompanying drawings, in the several iigures of which like reference numerals identify like elements, and in which: p

FIGURE l is an elevational view of a polarized relay embodying the subject invention;

FIGURE 2 is an elevational view, in section, of the polarized relay shown in FIGURE 1;

FIGURE 3 is a bottom View of the relay taken along lines 3 3 in FIGURE l;

FIGURE 4 is a sectionalized view Itaken along lines th-d in FEGURE l and more clearly illustrating the permanent magnet structure of the relay;

FIGURE 5 is a fragmentary View, partly in section, taken along lines 5--5 in FIGURE 1, illustrating a construction detail of the relay;

FIGURE 6 is a schematic representation of a remote control system employing a relay of the type shown in FIGURES 1-5;

FIGURES 7, 8 and 9 are sectional views illustrating alternative constructions of the relay structure; and

FIGURE 10 is a schematic diagram showing the application of the relay of FIGURE 9 to the remote control system of FIGURE 6.

FIGURES 1 and 2 illustrate a polarized relay comprising a magnetic motor 10 constituted by a magnetic structure which includes an energizing coil 11 for establishing magnetic flux in the structure and `a resilient armature 12 of a conductive material. The armature iS E-shaped having a pair of outer arms 13, 14 and an intermediate arm 15 which serves as a magnetic pole and also as a displaceable electrical connector. The free extremity of arm 15 is apertured to receive an insert-type contact terminal 16. Coil 11 is wound upon a `bobbin 17 of insulating material which encircles arm 15 and which supports a pair of terminals 1S to aford a connection between a source of energizing current, not shown, and coil 11. Another terminal 19 secured to a iiange of coil form 17 is electrically connected to arm 14 of armature 12 by means of a conductor 20 and facilitates making circuit connections including armature 12 to a control potential 110, see FIGURE 6.

A second magnetic structure 21 is provided and includes a pair of space opposed pole pieces comprising pole plates 22, 23 and pole mounting brackets 24, 25. The pole plates 22, 23 define an air gap 26 which is best shown in FIGURES 3 and 4. A pair of magnets 27 and 28 are carried by pole brackets 24, 25, respectively, and secured thereto by a suitable adhesive in [addition to their magnetic attraction. The magnets are positioned transversely of the air gap `at opposed ends thereof for estalblishing a substantially uniform magnetic flux across the gap. Pole brackets 24, 25 include respective shelves 29, 36 for supporting coil bobbin 17 and also pedestals 31, 32 for vmounting the relay upon a panel 33 of insulating material.

Means are provided for positioning magnetic motor 10 adjacent magnetic structure 21 with portion 15 of armature 12 in a reference position symmetrically disposed in gap 26. More particular, the pole plates 22, 23v and the brackets 24, 25 are apertured to accommodate a bushing 40 of insulating material which in turn receives the shankof a conventional bolt fastener 41 to insulatingly secure motor 10 to `structure 21. Wafers 42 of non-conductive material are inserted between outer arms 13, 14 of the armature and the pole pieces and between conductive washers 43 associated with the fasteners and the pole pieces to preclude a conductive path between the pole pieces and the armature.

While this construction comprises an inexpensive mounting arrangement, practical considerations respecting tolerance build-up of the pole piece members and spacers nullify any possibility that magnets 27, 28 can be precisely fitted between pole fbrackets 24, 25. It is therefore necessary that the thickness of the magnets be made less than the spacing that would obtain between the brackets if all the tolerances of the assembled pieces were minus. Accordingly, `an additional air gap 60 must be tolerated in this mounting arrangement. The inter- `ruption of the magnetic iiux by gap 60 creates a flux leakage and, in the `'absence of a corrective measure, causes asymmetrical operation of the relay. Such undesirable operation results since the ux distribution across air gap 60 is no longer uniform because a portion of the leakage flux from the north seeking pole of magnet 28 will return to the south pole through arm and pole plate 23, thus producing a greater flux density between arm 15 and plate 23 than between the arm and plate 22. In accordance with the invention the influence of this leakage is compensated by positioning magnets 27, 28 upon opposite pole brackets and at opposed ends of gap 26 thus insuring symmetrical operation of the relay.

The relay further includes a control device comprising a movalble element having a plurality of operating positions, specifically a rest position and first and second operated positions. The movable element may be a separate structural component carried by arm 15 of armature 12 to be displaced in respect of its operating positions in response to movement of the armature, or, the free end of armature portion 15 may constitute the movable element as shown in FIGURES 1 4. Where the control device is a work circuit, the arrangement further coniprises adjustable ` contacts 45, 46 positioned at opposite sides of air gap 26 for engagement by armature Contact 16 to complete a control circuit therethrough. Contacts 45, 46 are threadably received within pole brackets 24, 25, respectively, and secured by spring fasteners 47, 48. The control circuit may be extended through output terminals 49, 50 which are conductively affixed to pole brackets 24, 25.

The described polarized relay finds particular applic-ation in a remote con-trol system of the type disclosed in Patent 2,817,025 issued December 17, 1957 to Robert Adler. A portion of that control system is illustrated in FIGURE 6 and includes a transmitter 30 for developing a plurality of ultrasonic control signals of predetermined assigned frequencies. A pickup device comprising a microphone 31 is connected to an `amplifier 82 which in turn is connected to a limiter stage 83. A segregation network 84 is connected between limiter S3 and energizing coil 11 of the relay and comprises a discriminator system 85 having an output winding 86. The extremities of winding y36 are coupled to discriminator output terminals 95, 96 through rectifiers S7, 88. A pair of filter capacitors 89, 90 are connected between rectifiers 87, 88 and a plane of reference potential while an energy storage capacitor 91 is shunted eacross output terminals 95, 96 for preventing noise pulses of short duration from operating the relay.

A pair of resistors 97, 98 are series connected between output terminals 95, 96 and have their junction returned to a plane of reference potential. FIGURE 6 illustrates, schematically, the normally incomplete control circuit comprising Contact terminal 16 carried by arm 15 symmetrically disposed between adjustable contacts 45, 46 during the res-t position, that is, when coil 11 is de-energized. These contacts are electrically connected through pole bracket terminals 49, 50 to a reversible electric motor 92 which is mechanically coupled to a tuner mechanism 93 of a wave signal receiver, such as a television set.

In considering the operation of the described arrangement, it will be assumed that a pair of control signals of different frequencies, designated f1 and f2, are employed for effecting respective forward and reverse operation of tuner motor 92. Accordingly, a control signal f1 emanating from transmitter and intercepted by microphone 81 is amplified by unit 82 and applied to limiter 83. The frequency discriminator 85 is tuned to a center frequency )"0 intermediate frequencies f1, f2 and is conventional in operation. Output signals equal in magnitude but opposite in phase are developed between the extremities of winding 86 and a plane of reference potential in response to an input signal of frequency fo, while voltage components of unequal magnitude are developed in response Ato an input signal displaced from the center frequency.

Accordingly, principal as well as minor voltage components are developed between the extremities of winding S6 and ground in response to each of control signals f1, f2. Control signals of frequency f1 provide a principal D.C. current through energizing coil 11 and resistors 97, 98 in one direction and a minor current through the coil `and resistors in the opposite direction. In so far as the operation of the relay is concerned, however, the result is as though a single current, equal in magnitude to the difference between the opposed currents, flows through coil 11. Accordingly, coil 11 is energized and establishes a magnetic fiux of one polarity in armature 15 to polarize its free end correspondingly. Conversely, control signals of frequency f2 estafblish the opposite polarity field and pole conditions in the armature. Thus, the polarity and strength of the variable magnitude field of the relay are determined by the amplitude of the received control signal and the relative position of the signal, frequencywise, with respect to the center frequency fo. The free end 15 of the armature, which is polarized accordingly, is `displaced from its rest position into engagement with one of contacts 45, 46. Assuming that the end 15 of the armature becomes polarized as a magnetic north pole in the presence of control signals of frequency f1, since like poles repel, the armature is displaced toward the south pole of magnet 28 to a first operating position in which an electrical connection is effected between armature contact 16 and `contact 46. In this manner la source of potential is connected through conductor 20 and arm-ature 12 to motor 92 to initiate a forward rotation of tuner 93.

In similar fashion, control signals of frequency f2 polarize the free end of the armature in an opposite sense as a magnetic south pole. As 'a result, the arm 15 is displaced to its second operating position to effect an electrical connection between armature contact 16 and contact 45 and complete an electrical circuit which energizes motor 92 for rotation in a reverse direction.

FIGURE 7 illustrates an alternative construction of the relay wherein a pair of unitary pole pieces 55, 56 are substituted for the pole plates 22, 23 and brackets 24, 25 shown in FIGURE 4. Pole pieces 55, 56 include upper lip portions 29', 30 for supporting bobbin 17 of coil 11 and pedestals 31', 32 for mounting the relay upon panel 33. The pole pieces further include respective bosses 57, 53 to provide lateral stability for contacts 45, 46.

FIGURE 8 shows `a further embodiment likewise comprising a magnetic motor `10 and a cooperating permanent magnet structure 21. The magnetic structure of motor 10 includes an energizing coil 11 and a resilient U-shaped armature y12 having a fixed arm 61 and a displaceable free arm V62 terminated by a contact 16 and serving as a magnetic pole. Structure 21' differs from the principal embodiment only in that the armature contact 16 and its adjustable mating contacts, not shown, are disposed adjacent one end of the pole pieces. The mounting arrangement for motor 10 and structure 21 is substantially the same a-s that shown in FIGURE 5 with the exception that the fastener comprises a bushing 40 of rectangular configuration for `keying the pole plates and the fixed end 61 of the armature to prevent rotational displacement of the armature during operation.

The arrangements of FIGURES 7 and 8 perform in substantially the same manner as the iirst-described embodiment.

The relay modification depicted in FIGURE 9 comprises a magnetic motor 10" and an associated magnetic structure 21". lMotor =10 consists of a magnetic structure which includes a pair of series-connected energizing coils 70, 71 encircling center arm 15 of the larmature and having respective terminals 99, i100 to permit electrical connections to output terminals 95, 96 of network 84. In other respects, the dual-coil relay construction is substantially identical'to the structure disclosed in FIGURES land it is especially useful in the control system of FIGURE 46. 'Ihe juncture of coils 70, 71 is maintained at reference potential as shown in FIGURE and the principal D.-C. cur-rent derived in response to control signals of frequency f1. ilows through coil 70 only, while the minor D.C. current is applied to coil 71. The free end of the armature is polarized accordingly for selective actuation from its rest position to its first operating position in the manner previously described. The actuation of the armature, of course, is in the opposite lsense in response to control signals of frequency f2.

The use of a pair of series-connected coils provides a readily accessible D.-C. return for the energizing currents and eliminates the resistor string 97 98 shunted across the terminals of coil 11 in the first-described embodiment. Further, the sensitivity of lthe relay is enhanced by a dualcoil construction since no power is required for a resistive divider.

The subject invention'thus provides a polarized relay which employs a novel mounting arrangement for posivtioning the Vmagnetic structure of a polarized relay in such a fashion that the effective magnetic llux leakage distribution is altered so las to insure symmetrical operation of the relay. The relay structures, as has been demonstrated, lare particularly suitable for use in remote control systems. 1

While particular embodiments of the present invention have been shown and described, i-t is apparent that changes and modifications may be made therein without departing from theinvention in its broader aspects. 'Ihe aim ofthe appended claims, therefore, is to cover all such changes and modifications as wall within the true spirit and scope of the invention.

I claim:

1. A polarized `transducer comprising: a magnetic motor constituted by a magnetic structure and at least one energizing coil for establishing magnetic flux in said structure having a polarity determined by the polarity of the energizing current applied to said coil; a resilient armature included in said structure having a free end serving as a magnetic pole, polarized in accordance with the polarity of said ux; a second magnetic structure including -a pair of space opposed elongated pole pieces defining a principal air gap therebetween, and a pair of magnets carried at opposed ends of said pole pieces, respectively, and positioned 4transversely of said air gap at opposed ends thereof to define respective compensating air gaps for neutralizing leakage iiux thereby establishing a substantially uniform magnetic flux across said principal gap; and means for positioning said magnetic motor adjacent said second magnetic structure with said free end of said armature symmetrically disposed in said principal gap.

2. A polarized relay comprising: a magnetic motor constituted lby a magnetic structure and at least one energizing coil for establishing magnetic ux in said structure having a polarity determined by the polarity of the energizing current applied to said coil; a resilient armature included in said structure having a conductive free end comprising a displaceable electrical connector and serving as a magnetic pole, polarized in accordance with the polarity of said tiux; a second magnetic structure including a pair of space opposed elongated pole pieces defining a principal air gap therebetween, and a pair of magnets carried at opposed ends of said pole pieces, respectively, and positioned transversely of said air gap at opposed ends thereof to deiine respective compensating air gaps for neutralizing leakage iiux thereby establishing a substantially uniform magnetic ilux across said principal gap; means for positioning said magnetic motor adjacent said second magnetic structure with said connector in a reference position symmetrically disposed in said principal gap during operating intervals in which said coil is deenergized `but to one side of said principal gap during intervals 4in which said coil is energized; and a normally incomplete controlled circuit having a contact positioned to engage said connector to complete said circuit when said connector is displaced from said reference position.

3. A polarized relay comprising: a magnetic motor constituted by a magnetic structure and at least one energizing coil for establishing magnetic ux in said structure having a polarity determined by the polarity of the energizing current applied to said coil; a resilient armature included in said structure having a pair of outer arms and a displaceable conductive free arm comprising a displaceable electrical connector and serving as a magnetic pole, polarized in accordance with the polarity of said ilux; a second magnetic structure including a pair of space opposed elongated pole pieces deiining a principal air gap therebetween, and a pair of magnets carried at opposed ends of said pole pieces, respectively, and positioned transversely of said air gap at opposed ends thereof to define respective compensating air gaps for neutralizing leakage u-x thereby establishing a substantially uniform magnetic flux across said principal gap; means for insulatingly positioning said outer arms adjacent said second magnetic structure with said connector in a reference position symmetrically disposed in said principal gap during operating intervals in which said coil is de-energized Ibut to one side or the other of said principal gap during intervals in which said coil is energized, depending upon the polarity of said magnetic pole represented by said free arm; and a normally incomplete controlled circuit having adjustable contacts positioned at opposite sides of said principal gap and adjustable transversely of said principal gap to positions to engage said connector to complete said circuit when said connector is selectively displaced from said reference position in response to energization of said coil by an energizing current of predetermined polarity.

References Cited in the lile of this patent UNITED STATES PATENTS Vigren et al Mar. 15, 1960

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