US3134870A - Permanent magnet proximity switch - Google Patents

Description

y 26, 1964 D. E. REED ETAL 3,134,870

PERMANENT MAGNET PROXIMITY SWITCH Filed June 15, 1962 3 Sheets-Sheet 1 INVENTORS DONALD E. REED STANLEY F. REED BYm ATTORNEY y 26, 1964' D. E. REED ETAL 3,134,870

PERMANENT MAGNET PROXIMITY SWITCH Filed June 15, 1962 3 Sheets-Sheet 2 INVENTORS DONALD E. REED STANLEY E REED ATTORNEY M y 1964 D. E. REED ETAL 3,134,870

PERMANENT MAGNET PROXIMITY SWITCH Filed June 15, 1962 5 Sheets-Sheet 3 INVENTORS DONALD E. REED STANLEY F. REED ATTORNEY United States Patent PERMANENT MAGNET PROXIMITY SWITCH Donald E. Reed, Kensington, Md., and Stanley F. Reed,

McLean, Va., assignors to Space Components, Inc.,

Washington, I).C., a corporation of the District of Columbia 7 Filed June 15, 1962, Ser. No. 202,824 18 Claims. (Cl. 200-87) This invention relates to an electromagnetic snap action switch adapted to be actuated under the influence of a magnetic field.

According to one embodiment of the invention, an electromagnetic switch is magnetically biased to assume a quiescent or steady state position. Under the influence of an external magnetic field of suificient strength, the bias is overcome and contacts of the switch assume a different configuration. The bias provides stability and the switch thus exhibits special utility in environments subject to vibration.

According to another embodiment of the invention, an electromagnetic switch carries a rotatable actuating magnet whose pole faces spacially mesh with a plurality of flux buttons on the switch, slight angular movement of the actuating magnet elfecting actuation of the switch.

According to another embodiment of the invention, an electromagnetic switch carries a sliding magnet whose pole faces spacially mesh with a plurality of flux buttons on the switch, slight movement of the magnet effecting actuation of the switch.

The switch is characterized by the location of all moving elements and all electrical contacts in a completely controlled atmosphere. Typically, this is an inert atmosphere, but may be chosen as a reducing atmosphere. By such a construction, variations in switch operation which may be caused by variations in the ambient atmosphere are precluded.

In the drawings:

FIGURE 1 is a perspective view of the magnetic switch of this invention with an actuating magnet associated therewith.

FIGURE 2 is a view, partially broken, along line 2--2 of FIG. 1, the switch being in its quiescent state.

FIGURE 3 is a side elevational view of onecomponent of the switch.

FIGURE 4 is a perspective view of another component of the switch.

FIGURES 5 through 7 are schematic illustrations of the operation of the switch of FIGURES 1 to 4 inclusive.

FIGURE 8 is a schematic view, similar to FIGURES 5 through 7, showing the operation of a second embodiment of the invention.

FIGURE 9 is a partially schematic view of a third embodiment of the invention.

FIGURE 10 is a top plan view of a fourth embodiment of the invention.

FIGURE 11 is an elevational cross-sectional view, partly schematic, of the embodiment of FIGURE 10.

FIGURE 12 is a top plan view of a fifth embodiment of the invention.

FIGURE 13 is an elevational cross-sectional view, partly schematic, of the embodiment of FIGURE 12.

Referring now to FIGURES 1 and 2 of the drawings, the numeral 10 denotes the magnetically actuated switch of this invention and includes a circular, fiat cover plate 12 preferably of non-magnetic material such as nonmagnetic stainless steel. Plate 12 is provided with inserts 14, 16 and 18, commonly termed flux buttons, of unmagnetized magnetic material of low retentivity. These inserts may extend completely through the plate 12, as illustrated, or may be only partially imbedded. The inserts may be placed in the plate by soldering.

A generally cylindrical shell or wall 20, preferably integral with plate 12, terminates in a lower opening. Thus plate 12 and shell 20 define an open-ended cylindrical member. Preferably, shell 20 is formed of a non-magnetic material. In order to facilitate mounting of the switch the external surfaces of shell 20 may be threaded as indicated by the numeral 22 to facilitate insertion in a suitable mounting element.

The numeral 24 denotes a metallic ring which completely surrounds and is hermetically sealed to the periphery of a glass plate element 26. Numeral 28 denotes a plurality of conductor elements 30, 34 and 38 and a tubular vent element 40, all of which pass through 26 in hermetically sealed relation. Conductors 30, 34 and 38 are adapted to be inserted in a mounting socket and make electrical contact with an external circuit which is to be controlled by the switch. Conductors 30 and 34 terminate in flattened portions 35 and 37 respectively to which are aflixed electrical contact buttons 32 and 36. Conductor 38 extends higher than conductors 30 and 34 and terminates in a horizontally extending (note FIGURE 3) pivot element 42.

Referring now to FIGURE 4 of the drawings, the numeral 44 denotes a pivotable body element having top faces 46 and 48 inclined to each other at an angle A (see FIGURE 2). A permanent magnet 50, such as Alnico, is embedded in face 46 with one surface of the magnet preferably in the same plane as the face 46. Magnet 50 has the polarity indicated although it will be understood that it may have the opposite polarity. The other face 48 of body 44 is provided with a block of magnetic material 52 not permanently magnetized also having one surface preferably in the same plane as its face 48.

The numeral 51 denotes a'bushing made of electrically conducting material, for example silver-graphite, extending completely through body member 44 and carries a longitudinal bore 53. A pair of copper sheets 54 and 56 contact the sides of bushing 51 over a portion of the latters circumference and extend downwardly side by side. Sheets 54 and 56 carry contact buttons 58 and 60 adapted to cooperate, respectively, with contacts 32 and 36 of the base of the switch. Rotary electrical contact is made between pivot 42 and the interior of bushing 51. As shown at FIGURE 3, conductor 38 carries an abutment 39, greatly exaggerated for purposes of illustration, against which the left end of bushing 51 abuts. A washer 41 bears against the right edge of the bushing. A suitable crimp 43 is made on the end of pivot stud 42 after 44 and 41 are placed thereon.

Preferably, the body 44 is formed of an insulating nonmagnetic material, plastic having been found suitable. A plastic marketed under the tradename Dapon is acceptable since it does not give off gases at fairly high temperatures.

In assembly, all of the above described components are cleaned as by ultrasonic cleaning with a suitable solvent. Ring 24 is placed in the lower portion of shell 20 and silver solder S is applied and melted by induction heating. The ring 24, with plate 26 therein, hermetically seals the interior of 10, save for the vent tube 40. The switch is placed in a vacuum oven and baked for four hours at a temperature of approximately 400 F. to remove all volatile contaminants. Dry nitrogen is now introduced into vent tube 40 and the interior of the switch is flushed with this nitrogen approximately three or four times. In the last filling of the interior of the device, a mixture of nitrogen (93 percent) and helium (7 percent) is introduced at a positive pressure (10-12 pounds gauge has been found suitable) at room temperature.

The vent tube 40 is now sealed as by crimping or welding and solder may be added to the crimped portion if desired for more positive sealing.

In practice, 303 Stainless steel has been found suitable as the cover member 12 and shell 20 and silver solder has been found suitable for placing the flux buttons 14, 16 and 18 in plate 12, hermetically sealing them therein.

The switch has been found operable at temperatures up to 500 F. and will carry currents in the order of 15 amperes.

Referring now to FIGURES 5 through 7 of the drawings, the operation of the switch will now be given.

FIGURE 5 of the drawings illustrates, wholly schematically, the operation of the device to yield the quiescent position shown in FIGURE 2. The numerals at FIGURE 5 denote their corresponding three-dimensional counterparts of FIGURES 1 to 4 inclusive. Flux lines 100 and 102 emanating from permanent magnet 56 pass in the conventional direction as illustrated. These lines of flux find an easier path for return through element 14 than through flux buttons 16 and 18 since the latter are separated and are more distant from permanent magnet 50. As well known to workers in this art, flux lines 100 and 162 tend to diminish in length and elements 50 and 14 exhibit an attraction for each other. This drawing together compels the body 44 to assume the illustrated position in FIGURE 2.

FIGURES 6 and 7 illustrate the operation of the magnetic switch of this invention under the influence of an external magnetic field such as supplied by magnet M of FIGURE 1.

Referring now to FIGURE 6, it will be assumed that an external actuating magnetic field has the indicated polarity, the dotted lines indicating that the illustrated N and S poles are from the same magnet. The flux lines emanating from the left portion of the external north pole divide, part going through the flux button 14 and part going through the magnet 50 in the indicated direction to the left portion of the external south pole. The flux lines emanating from the right portion of the external north pole pass first through flux button 18 thence through element 52 and thence through flux button 16 to the right portion of the external south pole to thus complete the magnetic circuit. Because nearly all of the magnetic fiux lines from the right portion of the external magnetic field pass through element 52 while only a portion of the flux lines from the left portion of the external magnetic field pass through magnet 50 (the remainder of the flux lines from the left portion of the external magnetic field passing along the length of flux button 14) there will be a greater upward force acting on element 52 than on permanent magnet 50, if the strength of the external actuating field is sufiicient to overcome the biasing action described with reference to FIGURE 5, and thus the body 44 will assume a position opposite to that illustrated in FIGURE 2 and contact 60 will now abut contact 36 thus forming a new electrical path through the switch.

Reference now to FIGURE 7 of the drawings illustrates that the position of the switch is changed from its quiescent or steady state position even though the polarity of the external magnetic field may be opposite to that illustrated in FIGURE 6. Nearly all of the magnetic lines of force emanating from the right portion of the external north pole pass through flux button 16, element 52, flux button 18 and thence return to the right portion of the external south pole. Nearly all of the fiux lines from the left portion of the external north pole pass through flux button 14 and thence to the left portion of the external south pole. Few or none pass through permanent magnet 50 in the indicated direction, since it is both more remote than flux button 14 and the fiux lines are in opposition to the field of permanent magnet 50, as illustrated by the shortest curved lines. The upward force on element 52 will be greater than the upward force on element 50 because there are more flux lines threading through 16 and 18 and 52 than through 14 and 4 50 and the switch will assume a position opposite to that illustrated in FIGURE 2 and a new electrical path will be established in the switch.

It will be observed that the presence of the elongated flux button 14 also serves to protect the magnet 50 lying directly beneath. As apparent from the above discussion, no matter what the direction of lines of flux from the external actuating field, a portion of these flux lines always passes through flux button 14 thereby serving to weaken the effect or influence of these lines upon permanent magnet 50. Thus, referring to FIGURE 7, in a case wherein the external field acts in a direction counter to the field of permanent magnet 5-0, the presence of the flux button 14 serves to divert or divide the external flux lines thus weakening their effect upon magnet 50 and preventing it from becoming demagnetized.

In the description of FIGURES 6 and 7, it has been assumed that the external actuating field has been of a width to span the entire flux button array. Thus, in FIGURE 6, the north pole of the external actuating magnet has been assumed to be wide enough to span the distance from fiux button 18 to flux button 14, similarly, its south pole has been assumed to be wide enough to span the distance between flux button 16 and flux button 14. In the preferred manner of operation, it is not necessary that the external actuating field emanate from such wide pole faces. Thus, referring to FIGURE 1 of the drawings, the external magnet M may lie directly over flux buttons 16 and 18 and not extend over fiux button 14. It will be clear, from the previous discussion, that if a narrower actuating field is employed acting directly above flux buttons 16 and 18 of FIGURES 6 and 7, the switch will be actuated away from the bias position whether it has the polarity indicated at FIGURE 6 or the polarity indicated at FIGURE 7 if the actuating field is strong enough.

FIGURE 8 of the drawings illustrates a second embodiment of the invention, similar in all structural respects to the first embodiment save for the presence of two flux buttons and 141 in lieu of the single flux button 14. Flux buttons 140 and 141 occupy the same positions as fiux button 14 with respect to magnet 50 and plate 12. In this embodiment of the invention, the magnetic saturation of element 52 is chosen to be greater than that of permanent magnet 50. More flux lines from a sufficiently strong external actuating field will thence thread through element 52 than through magnet 56 regardless of the polarity, i.e., that of FIGURE 6 or that of FIGURE 7, of the external actuating field. Hence the quiescent biasing force, that due to the attraction between magnet 50 and flux buttons 140 and 141, will be overcome and the switch actuated under the influence of the external actuating field no matter what its orientation if the strength of the external field is great enough.

FIGURE 9 of the drawings illustrates a third embodiment of the invention. Referring now to FIGURE 9, the numeral 440 denotes a body element similar in configuration to element 44 of the first embodiment. In lieu of a single permanent magnet 50 and an unmagnetized magnetic element 52, two permanent magnets 590 and 501 are illustrated as occupying the same positions as ele ments 50 and 52 respectively (note FIGURE 4). Flux buttons 160, 161, and 181, occupy positions homologous to those indicated at FIGURE 8 of the drawings, the fluxbuttons being positioned in the cover plate 12, the latter being omitted from the drawing for purposes of clarity. The numerals 200, 202, 204 and 206 denote pole faces of annular permanent magnet 268 having the indicated polarities. The dashed line representations of pole faces 200, 202, 204 and 206 show their positions relative to the other elements when permanent magnet 208 is in its operative position, i.e., its upper portion tilted toward the viewer so that its pole faces lie in a plane parallel to and slightly above the plane of the flux buttons. The pole faces are integral with the annular magnet 208 and extend downwardly therefrom as illustrated.

In order to actuate the magnetic switch of this embodiment, the magnet 208 (when in its operative position) is rotated counter clockwise. The pole faces will then occupy positions superposed with respect to the flux buttons. Thus, face 202 moves towards button 161, face 200 moves towards button 160, face 206 moves towards button 180 and face 204 moves towards button 181. The flux lines emanating from face 206 pass through button 180 and then to the south pole of magnet 501, thence to the north pole ofv magnet 501, up through button 160 and enter magnet 208 through face 200. Magnet 501 thus moves towards buttons 160 and 180 while the flux from faces 2G2 and 204 causes magnet 500 to move away from buttons 161 and 181. The upper portion of body 440 thus rotates in the direction of arrow A. In order to reverse the rotation of body 440, magnet 208 is rotated clockwise.

Upon return of annular magnet 208 to the illustrated central position (faces 206, 200, 202, 204 not lying over but spaced between buttons 161, 181, 180, 166)), the body 440 remains in the last position assumed, due to the greater flux passing from magnet 500 (or 501) through the associated nearby flux buttons, as compared to flux from magnet 501 (or 500) through the slightly more distant flux buttons.

Hence body 440 can assume either of two quiescent positions, the position assumed being dependent on the previous rotation of magnet 208. I

If desired, less than all of the pole faces 209-206 may be employed, although the operation is then somewhat less reliable.

The radius of the concave pole faces identified as 210 very closely approximates the radius of the flux buttons and hence only slight angular movement of magnet 203 is required to actuate the switch. Actuating magnet 298 may be mounted directly on the switch or it may be coupled to a shaft or other rotatable member fixedly positioned relative to the switch.

Referring now to FIGURES l0 and 11 of the drawings, still another embodiment of the invention is illustrated which employs a translating or sliding actuating magnet 227 in lieu of the rotary magnet 20% in the embodiment of FIGURE 9. Permanent magnet 227 has six pole faces 221, 222, 223, 224, 225 and 226 with polarities N, S, N, S, N and S, as indicated at FIGURE 10. When the actuating magnet is moved to the right, direc tion B, pole face 221 moves closer to flux button 161, pole face 222 moves closer to flux button 160, pole face 224 moves closer to flux button 181 and pole face 225 moves closer to flux button 180. It will be understood that the flux buttons shown are mounted in plate 12, in the same manner as in the embodiment of FIGURE 9. With movement of actuating magnet 227 to the right, north pole face 221 moves towards flux button 161 so that the flux emanating from pole face 221 passes through this flux button and repels the north pole N of magnet 500 situated in rotatable member 440. Similarly, south pole face 224 moves towards flux button 181 and here also repulsion exists, now with the south pole S of magnet 500. Hence magnet 500 is repelled from flux buttons 161 and 181. South pole face 222 moves towards flux button 160 and the north pole N of permanent magnet 501 and. attraction exists. Similarly, north pole face 225 moves towards 180 and the south pole S of permanent magnet 501 is attracted. This results in upward movement of magnet 501 towards flux buttons 160 and 180. Thus rotation of the body 440, indicated by A of FIG- URE 11, occurs and the switch is actuated to a new position.

From the above described sequence, it is believed obvious that rotation in a direction opposite to A of FIG- URE 11 will occur when actuating magnet 227 is moved to the left, direction C.

With actuating magnet 227 in a central position, i.e.,

the position indicated at FIGURE 10, the body 440 will remain in its last assumed position. The edges of the pole faces are so contoured as to closely complement the periphery of flux buttons 160, 161, 180 and 181, as in the embodiment of FIGURE 9, so that only slight translating motion in either direction is required to effect the switch actuation.

From a consideration of this embodiment of the invention, it will be appreciated that if magnet 227 is rotated such that flux button 180 lies between pole faces 224 and 225 and flux button 181 lies between pole faces 221 and 222, etc., the actuation of body 440 is caused by motion of magnet 227 in the direction at right angles to the indicated directions B and C.

Referring now to FIGURES l2 and 13 of the drawings, still another embodiment of the invention is illustrated which employs another modification of a translating actuating magnet. Except for the reversal of the polarity of magnet 561 from the polarity shown in FIGURE 9, this embodiment is similar to the embodiments of FIGURES 9 and 10 save for the specific configuration of the actuating magnet. The numeral 337 denotes an actuating magnet adapted to travel along a path substantially parallel to the plane of flux buttons 160, 161, 180 and 181 placed in the plate 12 (not illustrated). Magnet 337 is provided with three ridge portions extending completely thereacross, the lower faces of which define magnetic pole faces 329, 331 and 333 having the indicated polarities. Preferably, in order to effect switch actuation upon only slight movement of the actuator, the ridges include curved sides complementary to the flux buttons, one side of which is indicated by the numeral 335 in FIGURE 12. The poles of the permanent magnets which lie in body 440, and which are situated below the flux buttons, have polarities as in dicated at FIGURE 12 by N and S.

Referring now to FIGURE 12, upward motion shown byarrow A of actuator 337 causes pole face 333 to move closer to flux buttons 18%) and 181, similarly, pole face 331 moves closer to fiux buttons and 161. Considering now the left portion of FIGURE 12, it will be seen that upward motion results in an attraction of magnet 500 carried by rotatable body 440 while magnet 501 also carried by rotatable body 440, will be repelled. Thus the switch will be actuated. It is believed apparent that downward motion shown by arrow B will result in rotation of body 440 in a counter direction. The body 44.0 will remain in its last assumed position whenever actuating magnet 337 assumes a central position.

' We claim:

1. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having three apertures therein, one of said three apertures being' substantially larger than the other two of said three apertures, said apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said three apertures; an armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic material, an elongated permanent magnet, a block of unmagnetized magnetic material, and a switch arm carrying a pair of electrical contacts mounted on said body element; two electrical contacts mounted within and supported by said shell; and said armature so correlated to said cover plate that the larger one of said three inserts is positioned over said permanent magnet and said other two of said inserts are each positioned over said block of magnetic material, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said two electrical contacts supported by said shell.

2. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate 7 integral with said shell, said cover plate of non-magnetic material and having three apertures therein, and an insert of magnetic material sealed within each of said three apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a permanent magnet, a block of magnetic material, and an electrical contact mounted on said body element; an electrical contact mounted within said shell; and said armature so correlated to said cover plate that one of said three inserts is positioned over said permanent magnet and two of said inserts are positioned over said block of magnetic material, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted within said shell.

3. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having three apertures therein, one of said three apertures being substantially elongated and larger than the other two of said three apertures, said apertures being arranged to form a generally quadrangular configuration, with the elongated apertures along one side thereof, and an insert of magnetic material sealed Within each of said three apertures; an armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic insulating material, an elongated permanent magnet, an elongated block of unmagnetized magnetic material, said magnet and said block being aligned, and a switch arm carrying a pair of electrical contacts mounted on said body element; two electrical contacts mounted within and supported by said shell; and said armature so correlated to said cover plate that the largerone of said three inserts is aligned with and positioned over said permanent magnet and said other two of said inserts are aligned with and positioned over said block of magnetic material, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said two electrical contacts supported by said shell.

4. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic material, an elongated permanent magnet, a block of unmagnetized magnetic material having a magnetic saturation greater than that of said permanent magnet, and a switch arm carrying a pair of electrical contacts mounted on said body element; two electrical contacts mounted within and supported by said shell; and said armature so correlated to said cover plate that two of said four inserts are positioned over said permanent magnet and two of said four inserts are positioned over said block of magnetic material, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate .will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said two electrical contacts supported by said shell.

5. In an electrical switch operable by a magnetic actuator, the combinationcomprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a permanent magnet, a block of magnetic material having a magnetic saturation greater than that of said permanent magnet,

and an electrical contact mounted on said body element; an electrical contact mounted within said shell; and said armature so correlated to said cover plate that two of said four inserts are positioned over said permanent magnet and two of said four inserts are positioned over said block of magnetic material, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted within said shell.

6. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted Within and supported by said shell, said armature comprising a body element of non-magnetic insulating material, an elongated permanent magnet, an elongated block of unmagnetized magnetic material having a magnetic saturation greater than that of said permanent magnet, said magnet and said block being aligned, and a switch arm carrying a pair of electrical contacts mounted on said body element; two electrical contacts mounted Within and supported by said shell; and said armature so correlated to said cover plate that two of said four inserts are aligned with and positioned over said permanent magnet and two of said four inserts are aligned with and positioned over said block of magnetic material, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said two electrical contacts supported by said shell.

7. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic material, a pair of elongated permanent magnets and a switch arm carrying a pair of electrical contacts mounted on said body element; two electrical contacts mounted within and supported by said shell; and said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said four inserts are positioned over the other of said pair of permanent magnets, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said two electrical contacts supported by said shell.

8. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a pair of permanent magnets and an electrical contact mounted on said body element; an electrical contact mounted within said shell; and said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said four inserts are positioned over the other of said pair of permanent magnets, whereby the application of an oriented magnetic field of a predetermined strength across said cover plate will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted within said shell. 7

9. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, and an insert ofnmagnetic material sealed within each of said four apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a pair of permanent magnets and an electrical contact mounted on said body element; an electrical contact mounted within ,saidshell; said armature so correlated to said cover platethat two of said four'inserts are positioned over one of said pairofpermanent magnets and the othertwo of said "four inserts are positioned over the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said'cover plate and said armature, said'actuator comp-rising an annular magnet having four pole faces depending therefrom, said pole faces spaced in a manner so that they may either be spatially positioned between said four inserts or superposed thereover, and so polarized that adjacent pole faces are of pposite polarity, whereby the rotation of said actuator with respect to said cover plate will actuate said switch and cause-said electrical contact on said body element to engage said electrical contact mounted within said shell. 10. ,In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with'said shell, said cover plate of nonmagnetic material and having four apertures therein, said four apertures beingv arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each, of said four apertures; an armature rotatably mounted Within and supported by said shell, ,said armature comprising a body element of non-magnetic material, a pair of elongated permanent magnets and a switch arm carrying a pair of electrical contacts mount- ;ed on said body element; two electrical contacts mounted within and supported by said'shell; said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said four inserts are positioned over the other of saidpair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising an annular magnet having four pole faces depending therefrom, said pole faces spacedin a manner so that they may :either be spatially positioned between saidfour inserts or superposed thereover, so polarized that adjacent pole faces are of opposite polarity and so configured that the edge surfaces-thereof closely conform to the configuration of the inserts adjacent thereto, whereby the rotation of said actuator with respect to said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said pair :of electrical contacts mounted within said shell.

1 1. In an electrical switch operable by a magnetic actuator, the combinationcomprising: a shell; a cover plate integral with said shell, said cover plate of nonmagnetic material and having four apertures therein, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a pair of permanent magnets and an electrical contact mounted onsaid body element; an electrical contact mounted within said shell; said armatureso correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said 'four'inserts are positioned over the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plateand said armature, said actuator comprising a generally rectangular magnet'having siX1pole faces depending therefrom, said pole faces spaced in two parallel lines of three each so that said pole faces may either be spatially positioned to surround said four inserts or four of said siX pole faces be super- ,posed thereover, and so polarized that adjacent pole faces are of opposite polarity, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted within said shell.

12. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of nonmagnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic material, a pair of elongated permanent magnets and a switch arm carrying a pair of electrical contacts mounted on said'body element; two electrical contacts mounted within and supported by said shell; said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair ofvpermanent magnets and the other two of said four inserts are positioned over the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising a generally rectangular magnet having six pole faces depending therefrom, said pole faces spaced in two parallel lines of three each so that said pole faces may either be spatially positioned to surround said four inserts or four of said six pole faces be superposed thereover, so polarized that adjacent pole faces are of opposite polarity and so configured that the edge surfaces thereof closely conform to the configuration of the inserts adjacent thereto, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch .arm to engage one of said pair of electrical contacts mounted within said shell.

13. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a pair of permanent magnets and an electrical contact mounted on said body element; an electrical contact mounted within said shell; said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said four inserts are positioned over the other of said pair of permanent magnets; and a magnetic actuator opera- .tively associated with said cover plate and said armature,

said actuator comprising a generally rectangular magnet having three generally rectangular pole faces depending therefrom, said pole faces spaced so that said pole faces may either be spatially positioned to surround said four inserts or two of said three pole faces be superposed thereover, and so polarized that adjacent pole faces are of opposite polarity, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted Within said shell.

14. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic material, a pair of elongated permanent magnets and a switch arm carrying a pair of electrical contacts mounted on said body element; two electrical contacts mounted within and supported by said shell; said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said four inserts are positioned over the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising a generally rectangular magnet having three generally rectangular pole faces depending therefrom, said pole faces spaced so that said pole faces may either be spatially positioned to surround said four inserts or two of said three pole faces be superposed thereover, so polarized that adjacent pole faces are of opposite polarity and so configured that the edge surfaces thereof closely conform to the configuration of the inserts adjacent thereto, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said pair of electrical contacts mounted within said shell.

15. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of non-magnetic material and having four apertures therein, and an insert of magnetic material sealed within each of said four apertures, an armature rotatably mounted within said shell, said armature comprising a body element, a pair of substantially elongated permanent magnets and an electrical contact mounted on said body element, each of said pair of magnets having two ends with a north pole at one end and a south pole at the other end, said magnets aligned in parallel relation with the south pole of one magnet positioned adjacent the south pole of the other magnet, the poles thereof forming a generally rectangular configuration; an electrical contact mounted within said shell; said armature so correlated to said cover plate that two of said four inserts are positioned over one of said pair of permanent magnets and the other two of said four inserts are positioned over the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising a generally rectangular magnet having six pole faces depending therefrom; said pole faces spaced in two parallel lines of three each so that said pole faces may either be spatially positioned to surround said four inserts or four of said six pole faces be superposed thereover, and so polarized that adjacent pole faces are of opposite polarity, whereby the translation of said actuator with respect to said cover plate Will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted within said shell.

16. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of nonmagnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures, an armature rotatably mounted within and supported by said shell, said armature comprising a body element of nonmagnetic material, a pair of substantially elongated permanent magnets and a switch arm carrying a pair of electrical contacts mounted on said body element, each of said pair of magnets having two ends with a north pole at one end and a south pole at the other end, said magnets aligned in parallel relation with the south pole of one magnet positioned adjacent the south pole of the other magnet, the poles thereof forming a gencrally quadrangular configuration; two electrical contacts mounted within and supported by said shell; said armature so correlated to said cover plate that two of :said four inserts are positioned over the ends of one of said pair of permanent magnets and the other two of :said four inserts are positioned over the ends of the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising a rectangular magnet having six pole faces depending therefrom, said pole faces spaced in two parallel lines of three each so that said pole faces may either be spatially positioned to surround said four inserts or four of said six pole faces be superposed thereover, so polarized that adjacent pole faces are of opposite polarity and so configured that the edge surfaces thereof closely conform to the configuration of the inserts adjacent thereto, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said pair of electrical contacts mounted within said shell.

17. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell, said cover plate of nonmagnetic material and having four apertures therein, said four apertures being arranged to form a generally quadrangular configuration, and an insert of magnetic material sealed within each of said four apertures; an

armature rotatably mounted within and supported by said shell, said armature comprising a body element of non-magnetic material, a pair of substantially elongated permanent magnets and a switch arm carrying a pair of electrical contacts mounted on said'body element, each of said pair of magnets having two ends with a north pole at one end and a south pole at the other end, said magnets aligned in parallel relation with the south pole of one magnet positioned adjacent the north pole of the other magnet, the poles thereof forming a generally rectangular configuration; two electrical contacts mounted within and supported by said shell; said armature so correlated to said cover plate that two of said four inserts are positioned over the ends of one of said pair of permanent magnets and the other two of said four inserts are positioned over the ends of the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising a generally rectangular magnet having three generally rectangular pole faces depending therefrom, said pole faces spaced so that said pole faces may either be spatially positioned to enclose said four inserts or two of said three pole faces be superposed thereover, so polarized that adjacent pole faces are of opposite polarity and so configured that the edge surfaces thereof closely conform to the configuration of the inserts adjacent thereto, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause one of said pair of electrical contacts on said switch arm to engage one of said pair of electrical contacts mounted within said shell.

18. In an electrical switch operable by a magnetic actuator, the combination comprising: a shell; a cover plate integral with said shell; said cover plate of nonmagnetic material and having four apertures therein, and an insert of magnetic material sealed within each of said four apertures; an armature rotatably mounted within said shell, said armature comprising a body element, a pair of substantially elongated permanent magnets and an electrical contact mounted on said body element, each of said pair of magnets having two ends with a north pole at one end and a south pole at the other end, said magnets aligned in parallel relation with the south pole of one magnet positioned adajcent the north pole of the other magnet, the poles thereof forming a generally rectangular configuration; an electrical contact mounted within said shell; said armature so correlated to said cover plate that two of said four inserts are positioned over the ends of one of said pair of permanent magnets and the other two of said four inserts are positioned over the ends of the other of said pair of permanent magnets; and a magnetic actuator operatively associated with said cover plate and said armature, said actuator comprising generally rectangular magnet having three generally rectangular pole faces depending therefrom, said pole faces spaced so that said pole faces may either be spatially positioned to enclose said four inserts or two of said three pole faces be superposed thereover, and so polarized that adjacent pole faces are of opposite polarity, whereby the translation of said actuator with respect to said cover plate will actuate said switch and cause said electrical contact on said body element to engage said electrical contact mounted within said shell.

UNITED STATES PATENTS McLeod Nov. 6,

Abel Feb. 20,

Peay et a1. June 19,

FOREIGN PATENTS Germany Oct. 12,

Claims (1)

1. IN AN ELECTRICAL SWITCH OPERABLE BY A MAGNETIC ACTUATOR, THE COMBINATION COMPRISING: A SHELL; A COVER PLATE INTEGRAL WITH SAID SHELL, SAID COVER PLATE OF NON-MAGNETIC MATERIAL AND HAVING THREE APERTURES THEREIN, ONE OF SAID THREE APERTURES BEING SUBSTANTIALLY LARGER THEN THE OTHER TWO OF SAID THREE APERTURES, SAID APERTURES BEING ARRANGED TO FORM A GENERALLY QUADRANGULAR CONFIGURATION, AND AN INSERT OF MAGNETIC MATERIAL SEALED WITHIN EACH OF SAID THREE APERTURES; AN ARMATURE ROTATABLY MOUNTED WITHIN AND SUPPORTED BY SAID SHELL, SAID ARMATURE COMPRISING A BODY ELEMENT OF NON-MAGNETIC MATERIAL, AN ELONGATED PERMANENT MAGNET, A BLOCK OF UNMAGNETIZED MAGNETIC MATERIAL, AND A SWITCH ARM CARRYING A PAIR OF ELECTRICAL CONTACTS MOUNTED ON SAID BODY ELEMENT; TWO ELECTRICAL CONTACTS MOUNTED WITHIN AND SUPPORTED BY SAID SHELL; AND SAID ARMATURE SO CORRELATED TO SAID COVER PLATE THAT THE LARGER ONE OF SAID THREE INSERTS IS POSITIONED OVER SAID PERMANENT MAGNET AND SAID OTHER TWO OF SAID INSERTS ARE EACH POSITIONED OVER SAID BLOCK OF MAGNETIC MATERIAL, WHEREBY THE APPLICATION OF AN ORIENTED MAGNETIC FIELD OF A PREDETERMINED STRENGTH ACROSS SAID COVER PLATE WILL ACTUATE SAID SWITCH AND CAUSE ONE OF SAID PAIR OF ELECTRICAL CONTACTS ON SAID SWTICH ARM TO ENGAGE ONE OF SAID TWO ELECTRICAL CONTACTS SUPPORTED BY SAID SHELL.

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