US3211858A - Latching relay and electromagnetic actuator therefor - Google Patents

Description

Oct. 12, 1965 w. F. JUPTNER 3,211,858

LATCHING RELAY AND ELECTROMAGNETIC ACTUATOR THEREFOR Filed June 21, 1963 2 Sheets-Sheet 1 m; 56 Z 220, 440 i I 60 INVENTOR. 246 WILLIAM F. JUPTNER T" "W W ATTORNEY ATTQRNEY /6a Q l 60a az fifl 30 INVENTOR. WILLlAM E JUPTNER FIG.8

Oct. 12, 1965 w. F. JUPTNER LATCHING RELAY AND ELECTROMAGNETIC ACTUATOR THEREFOR Filed June 21, 1963 United States Patent i 3,211,858 LATCHING RELAY AND ELECTROMAGNETIC ACTUATQR THEREFOR William F. Juptner, Laguna Beach, Calif., assignor to Babcock Electronics Corporation, Monrovia, Calif., a corporation of California Filed June 21, 1963, Ser. No. 289,637

9 Claims. (Cl. 200-93) The present invention relates generally to latching relays and electromagnetic actuators therefor, and more particularly to such electromagnetic devices which are extremely small and compact.

Although latching relays have been Well known in the electronic art for many years, prior devices of this kind have not been particularly desirable for certain applications. Such prior devices have been so constructed as to be relatively large and heavy. Accordingly, they have not been useable in applications where size and weight of the electronic components are important.

Today, many electronic components are used in equipment such as test probes and capsules for use in exploring outer space. In view of the power requirements for putting such a probe or capsule into orbit or in flight in outer space, the size and weight of a payload becomes exceedingly important. Accordingly, there has developed an acute need for electronic components of minimium size and Weight.

It 'is an object of the present invention to teach the construction of an electromagnetic actuator which is small and compact.

Another object of the present invention is to provide a small, compact electromagnetic latching actuator which can be latched in either of two extreme positions.

Another object of the present invention is to provide an electromagnetic actuator as characterized above which can be magnetically latched in either of its extreme positions.

A further object of the present invention is to provide an actuator as characterized'above which can be operated from one position to another merely by momentary energization of suitable electromagnetic means.

Another object of the present invention is to provide an electromagnetic latching actuator as characterized above wherein the electromagnetic winding for switching the device from one latched position to another is wound about the armature thereof.

A further object of the present invention is to provide an electromagnetic latching actuator as characterized) above having an electromagnetic winding which is tubular in shape providing an opening wherein the armature is movable between its said extreme positions.

A still further object of the present invention is to provide a latching relay having a small compact electromagnetic actuator as characterized above for controlling one or more pairs of electrical contacts.

An additional object of the present invention is to provide an electromagnetic latching relay as characterized above wherein the contacts comprise a stationary resilient contact to be engaged by a movable contactor such as to develop in said contactor a biasing force which upon switching operation tends to move the armature such as to position the contactor in separated relation with respect to the stationary contact.

A still further object of the present invention is to provide a latching relay as characterized above wherein the armature is pivotally attached to a mounting member and the electromagnetic switching winding is wound about the armature and mounting member therefor to provide a small compact relay.

An additional object of the present invention is to provide an electromagnetic latching relay and actuator there- 3,211,858 Patented Oct. 12, 1965 for which is simple and inexpensive to manufacture, and which is rugged and dependable in operation.

The novel features which I consider characteristic of my invention are set forth with particularity in the appended claims. The device itself, however, both as to its organization and mode of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIGURE 1 is a fragmentary perspective view of an electromagnetic latching relay according to the present invention;

FIGURE 2 is a side elevational view of the latching relay, the cover having been removed;

FIGURE 3 is a top plan view of the armature assembly for the latching relay;

FIGURE 4 is a fragmentary sectional view taken substantially along line 44 of FIGURE 3;

FIGURE 5 is a side elevational view of the armature assembly taken substantially along line 5-5 of FIG- URE 3;

FIGURE 6 is a perspective view of the armature-coil assembly;

FIGURE 7 is an exploded perspective view of the latching relay; and

FIGURE 8 is a fragmentary top plan view of the contact assembly of the subject device.

Like reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to FIGURE 1 of the drawings, the embodiment chosen for illustration of the present invention generally comprises a base 10 wherein is positioned a cover 12 providing an enclosure 14 there within. Suitable terminal members 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h, 161 and 16 depend from base 10 for purposes which will hereinafter be described in detail. Cover 12 may be formed to firmly engage base 10, or it may be secured thereto as by welding, brazing, soldering, or the like to hermetically seal enclosure 14.

Positioned within enclosure 14 is an electromagnetic actuator 18. Such actuator comprises an armature assembly 20 as shown most clearly in FIGURES 3, 4 and 5 of the drawings. Assembly 20 comprises an armature 22 pivotally mounted on a mounting member 24 formed of magnetically impermeable material.

Armature 22 is formed of magnetically permeable material and is provided with a pair of opposite end portions 22a and 22b which are enlarged as at 22c and 22d, respectively, to provide armature pole pieces. As shown in FIGURE 5, the central or intermediate portion 22e of armature 22 is relatively narrow in its vertical dimension but wide in its horizontal dimension as shown at 22] in FIGURE 3. Intermediate portion 22@ is formed with a pair of oppositely disposed cylindrical extensions 22g and 22h which provide means for pivotally mounting armature 22 on mounting member 24. Such extensions are coined during the forming of armature 22 in a metal forming press provided for that purpose. That is, the armature is formed in a pressing operation out of a suitable piece of magnetically permeable material. During such forming operation sufiicient material is permitted to remain at the central portion of the armature to provide the cylindrical extensions 22g and 22h.

As will hereinafter become more apparent, the sides of the armature pole pieces 22a and 22b may be tapered for proper engagement with stationary magnetic pole pieces to be hereinafter described.

Mounting member 24 is provided with a fiat intermediate portion 24a and a pair of upstanding side flanges 24b and 240 which provide a generally U-shaped cross section for the mounting member. Each of the flanges 24b and 240 is formed with a generally square or rectangular cutout as at 24d and 240, respectively, for receiving a mounting strap 26 as will hereinafter be explained.

Member 24 is formed with a pair of enlarged opposite end portions 24f and 24g which are offset downwardly from the intermediate portion 24a.

Intermediate portion 24a is formed with a centrallylocated through opening 2411 for rotatably receiving the cylindrical extension 22h of armature 22 as shown in FIGURE 4. The periphery of such opening is bent upwardly as shown in said figure to provide an annular hearing surface for armature 22.

Mounting strap 26 is also provided with an opening 26a the peripheral edge of which is bent or offset to provide an annular bearing surface for the armature. Such opening 26a, as shown in FIGURES 3 and 4, receive the cylindrical extension 22g of armature 22. Mounting strap 26 is positioned within the cutouts 24d and 24e in the side flanges 24b and 240 of mounting member 24 while armat-ure 22 is positioned as shown in the drawings. Strap 22 is welded to the flanges of mounting member 24 to provide a unitary structure comprising armature 22 and mounting member 24.

Attached to each of the opposite ends of armature member 22 is a pair of actuators 28. Each such pair of actuators comprises a pair of spaced actuator rods 30 welded to the armature in depending position as shown in the drawings. An insulating spheroid 32 is mounted on the lower end of each such depending actuator rod 30. As will hereinafter become more apparent, such pairs of actuators 28 are operable to actuate electrical contacts of the latching relay.

As shown most clearly in FIGURE 6 of the drawings, the armature assembly 20 is provided with an electromagnetic winding to thereby effect an armature-coil assembly 34. Assembly 34 is formed by positioning about armature 22 and mounting member 24 a bobbin 36 formed of any suitable nonmagnetic material such as plastic or the like. Due to the enlarged opposite end portions 24 and 24g of mounting member 24, and due to the offset nature of such end portions as above described, the bobbin 36 is formed in two halves 36a and 36b which are separated longitudinally as shown in FIGURE 6.

The bobbin members 36:: and 36b are brought into mating engagement from opposite sides of the armature assembly 20 as indicated by the broken line showing of bobbin member 36b in FIGURE 6. Such members may be provided with suitable interlocking portions to insure proper alignment thereof and to provide bobbin 36 with the proper central through opening 360. Also, each bobbin member should be suitably formed so that the finished tubular bobbin 36 is provided with flanges as shown at 36d, 36c and 36f.

As shown in FIGURE 6 of the drawings, bobbin 36 is generally tubular in construction, having either a circular cross section or a square or rectangular cross section, as desired. The generally rectangular cross section has been found most desirable since it provides opening 360 with the most desirable size and shape for accommodating the intermediate portion of the armature assembly 20. That is, by providing through opening 360 with a generally rectangular cross section, the mounting member 24 and armature 22 thereon are most easily accommodated.

A first electromagnetic winding 40 is provided on bobbin 36 between flanges 36d and 36e. A second such winding 42 is provided thereon between the flanges 36c and 36f. Such windings are intended to be energized in opposite directions so as to effect magnetic polarization of armature 22 in opposite directions as will hereinafter be explained in detail. In the alternative, a single winding and means for reversely energizing it could be employed as will hereinafter become apparent.

A pair of frame members 44 and 46 are utilized in the device as magnetic flux conducting members as will hereinafter appear. Such frame members are identical in construction, and each com rises an elongated flux conducting portion as shown at 44:: and 46a respectively. At each end of such flux conducting portions, there is provided a stationary pole piece as shown at 44b and 440 with respect to frame member 44, and at 4611 and 460 with respect to member 46. The lower end portion of each such stationary pole piece is bent outwardly to provide a flange to be welded to the respective end portion of the mounting member 24.

Each of the frame members 44 and 46 is formed with a support, as shown at 44d with respect to member 44. The lower end portion of each support is formed with a pair of depending fastening tabs as shown at 44c and 44 The frame members 44 and 46 are formed in a metal forming press, and are made of magnetically permeable material.

As will hereinafter become more apparent, the electromagnetic actuator shown in the drawings and hereinabove described, provides a compact unitary structure. The relatively thin magnetic flux carrying portions 44a and 46a of the frame members 44 and 46 permit the bulk of the enclosure 14 to be occupied by the coil structure itself. As such, a large amount of magnetic flux is generated by the subject actuator as compared to the size and weight thereof.

Frame members 44 and 46 are attached to a pair of permanent magnets 50 and 52 which are positioned between each pair of opposed stationary pole pieces. The magnet 50 is interposed between the stationary pole pieces 44c and 46b at one end of the frames 44and 46 while the permanent magnet 52 is interposed between the pole pieces 44b and 460 at the other end thereof. Such magnets are held in firm abutting relation with the respective pole pieces by mounting clips 54.

Each mounting clip 54 is generally U=shaped in con struction and comprises a pair of side portions 54a and 54b, and in intermediate portion 540. Also, each clip 54 is provided with a supporting flange as shown at 54d in FIGURE 7. Whereas each permanent magnet is positioned between the pole faces of the opposed stationary pole pieces, the side portions 54a and 54b of mounting clips 54 are positioned on the outside thereof. That is, as shown in FIGURES 1, 2 and 7 of the drawings, the side portion 54a of clip 54 is positioned against the outer surface of pole piece 44b while the side portion 54b is against the outer surface of the pole piece 460. The supporting flange 54d is positioned beneath the permanent magnet to retain the same in elevated position with respect to the armature 22. The side portions 54a and 54b are then fastened to the respective stationary pole pieces as by spot welding, soldering or the like. Such arrangement firmly retains the permanent magnets 50 and 52 in abutting relation with the respective pole pieces.

After the frame members and permanent magnets have been fastened together to provide a unitary structure, the armature-coil assembly 34 is inserted upwardly between the supports 44d and 46d of the frame members 44 and 46 as shown more clearly in FIGURE 7. After this is accomplished, the enlarged end portions 24 and 24g of mounting member 24 are welded to the respective outwardly extending lower end portions of the stationary pole pieces. This provides a unitary structure of the armature-coil assembly 34 and the frames 44 and 46. To hold the coil assembly in proper relation to the armature 22, the supports 44d and 46d may be bent inwardly slightly.

As will hereinafter become more apparent, the permanent magnets 50 and 52 are arranged in parallel circuit relation such that they cooperate in polarizing the frame members 44 and 46. That is, such magnets are oriented such as to provide frame member 44 with a given magnetic polarity and to provide frame member 46 with the opposite magnetic polarity.

Mounted on top of base member is the contact assembly 56. The aforementioned terminal members 16a, 16b, 16c, 16d, 167, 16g, 16h, 191 and 16 are insulatedly mounted in base member 10 in such a manner as to provide terminal posts within the enclosure 14. Each such terminal post is electrically and magnetically independent of all other terminal posts as provided by appropriate insulating means.

On each of the corner terminal posts, namely posts 16a, 16h, 16h and 16i, there is provided a generally L shaped stationary contact 60. One end of each stationary contact 60 is reversely bent as at 60a to provide mounting means for mechanically fastening. the contact to the respective terminal post. To insure good electrical contact between the contact and post, a bead of solder as shown at 62 may be provided within the end portion 60a.

The free end 6011 of each stationary contact is bent as shown in the drawings to provide a flat contact surface. Also, each stationary contact 60. is formed of resilient material which exhibits good electrical conductivity.

Positioned between each pair of stationary contacts is an elongated contactor 64. The contactor 64 between the stationary contacts on mounting posts 16a and 16b is fastened to post 16g by means of a generally L-shaped bracket 65. In like fashion, the contactor positioned between contacts on posts 16h and 161' is anchored to mounting post 16c. The L-shaped bracket 65 of each contactor may be firmly secured to the respective mounting post by a bead of solder 66. Each contactor 64 is formed with a relatively straight end portion 64b for good electrical contact with the contact surfaces of the respective stationary contacts.

When the electromagnetic actuator 18 is attached to base 10, the pair of insulating spheroids 32 at each end of armature 22 are caused to straddle the end portion 64b of the respective contactor 64 as shown most clearly in FIGURES 3 and 8 of the drawings. To attach the actuator 18 to base 10, the mounting tabs at the lower end of the support formed in each of the frame members 44 and 46 are inserted into suitable cutouts formed in the sides of base 10. Such tabs may be welded in such positions to firmly secure the electromagnetic actuator to base 10.

The ends of winding 42 are connected to terminal posts 16d and 16a as shown in FIGURE 7'. In like manner, the winding 40 has its opposite ends connected to terminal posts 16f and 16 As will hereinafter become more. apparent, the windings 40 and 42 must be energized in opposite directions. That is, if the direction of current flow through winding 4!) is in a clockwise direction, the current flow through winding 42 must be in a counterclockwise direction. This is necessary so that energization of windings 40 and 42 causes opposite magnetic polarization of the armature 22.

After the electromagnetic actuator 18 has been properly mounted on base 10 and all of the necessary electrical connections have been made, the cover 12 is positioned over the entire mechanism as shown in FIGURE 1.

The subject latching relay may be mounted in an appropriately formed socket for receiving the aforedescribed terminal members.

The subject latching relay operates generally as follows.

With the permanent magnets 50 and 52 properly positioned as above explained, the frame members 44 and 46 and their respective stationary pole pieces are caused to be oppositely magnetically polarized. As such, the armature 22 is free to pivot about its axis, as afforded by cylindrical extensions 22g and 22h, into engagement with either pair of diagonally positioned stationary pole pieces. That is, as shown in FIGURE 7, the armature can be positioned such that the pole piece 22b is in engagement with the stationary pole piece 44b of frame member 44. Such positioning of the armature causes the opposite armature pole piece 22a to be moved into engagement with stationary pole piece 46b of frame member 46. As a result, there is provided a pair of parallel magnetic circuits for holding armature 22 in this position. A first circuit is provided from the side of magnet 52 in engagement with stationary pole piece 44b through pole piece 44b, armature pole piece 22b, armature 22, armature pole piece 22a, stationary pole piece 46b, flux conducting portion 46a of frame member 46, and the stationary pole piece 460 to the other side of permanent magnet 52. V

The second magnetic circuit is completed from the side of permanent magnet 50 in engagement with stationary pole piece 440 through magnetic flux conducting portion 44a of frame 44, stationary pole piece 44b, armature pole piece 22b, armature 22, armature pole piece 22a and stationary pole piece 46b to the other side of permanent magnet 50. Thus, there is provided two parallel magnetic circuits which aid in maintaining armature member 22 in one of its extreme positions.

With each pair of insulating spheroids 32 positioned on opposite sides of the respective contactor 64, such positioning of armature 22 causes the contactors to be in engagement with the stationary contacts on mounting posts 16b and 16h. That is, as shown in FIGURE 7, the armature is positioned in its extreme clockwise position, thereby causing the contactors 64 to be in their extreme clockwise positions completing electrical circuits between terminals 16g and 16b, and between terminals 16c and 16h.

It will be noted that armature 22 has been positioned as above described merely by the force of permanent magnets 50 and 52.

Thereafter, if the appropriate one of the windings 40 and 42 is energized, the armature 22 becomes polarized so as to cause armature pole piece 22b to be simultaneously repelled by stationary pole piece 44b and attracted by pole piece 460 while armature pole piece 22a is simultaneously repelled by stationary pole piece 46b and attracted by pole piece 44c. That is, by energizing the appropriate one of windings 40 and 42, the armature pole piece 22b is provided with the same magnetic polarity as stationary pole piece 44b. At the same time, the opposite armature pole piece 22a is polarized opposite to armature pole piece 22b, but since stationary pole piece 46b is polarized opposite to stationary pole piece 44b, the armature pole piece 22a is now repelled by stationary pole piece 44b.

Such energization of the coil on armature 22 overcomes the heretofore attractive force between armature 22 and the stationary pole pieces 44b and 46b to cause the armature to pivot to its opposite position. i

As shown in FIGURE 8, the inherent resiliency of the stationary contacts engaged by the contactors 64 is utilized to aid the relay to its opposite position. That is, with armature member 22 in its extreme clockwise position as above described, the stationary contacts 60 on mounting posts 16b and 16h are deformed sufliciently to develop a biasing force therein. As shown in broken lines in FIGURE 8, the respective stationary contacts are 'de formed sufficiently when the armature is in one of its extreme positions to develop biasing forces which operate against the contactors 64. When the armature '22 is being actuated to its opposite position by energization of one of the windings 40 and 42, the biasing force developed in the respective contacts aids the movement of the contactors 64 toward the opposite stationary contacts. Throughout such movement of armature 22, of course, the aformentioned reverse polarization thereof provides the major force for moving the armature to its opposite position. The polarization of armature 22 need only be momentary to cause the armature to be switched to its opposite position.

With the armature 22 in its extreme counterclockwise position, the contactors 64 are caused to' engage the stationary contacts on terminal post's 16a and Mi. Thus the aforedescribed circuits are interrupted, and the circuits including terminals 16a and 16g, and 160 and 16i are completed.

While the armature is in its counterclockwise position, a different pair of parallel magnetic circuits are operable for retaining the armature in such position. Thereafter, upon energization of the other of the windings 40 and 42, the latching relay is switched to its original position.

It should be particularly noted that the construction of the subject latching relay results in a very small compact structure which is capable of performing work heretofore accomplished only by larger devices. Mounting of the electromagnetic windings on the armature assembly enables the electrical energy to be used more efficiently, and permits the magnetic flux conducting frame to be smaller and more compact.

Although the embodiment chosen for illustration of the present invention is in the form of a double pole double throw switch, it is contemplated within the scope of the present invention that substantially any desired Contact configuration may be employed.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended ela im s.

I claim:

1. An electromagnetic actuator comprising in combination, a pair of spaced magnetie frame members, mag iietic means inteposed between said frame members to oppositely magnetically polarize said members, a mounting member, an elongated armature pivotally mounted on said mounting member between said frame members having opposite end portions individually engageable with said frame members to complete the magnetic circuit for said magnetic means, and electromagnetic means on said armature comprising a tubular bobbin about said mounting member and armature and an electromagnetic winding on said bobbin energizable to polarize said armature to cause said end portions to be magnetically repelled from their respective frame members, whereby said armature is caused to rotate to a different position.

2. An electromagnetic actuator comprising in combination, a mounting member, a pair of magnetic frame members fixed to said mounting member in spaced relation, a permanent magnet interposed between said frame members to oppositely magnetically polarize said members, an elongated armature pivotally mounted on said mounting member having opposite end portions individually engageable with said frame members, and electromagnetic means comprising a tubular bobbin positioned about said mounting member and armature comprising a pair of electromagnetic windings individually energizable for opposite polarization of said armature to thereby control the rotative position of said armature with respect to said frame members.

3. A latching relay comprising in combination, a mounting member, a pair of magnetic frame member fixed to said mounting member in spaced relation, a permanent magnet interposed between said frame members to oppositely magnetically polarize said members, a magnetically permeable elongated armature pivotally mounted on said mounting member having opposite end portions which are individually attracted to opposite ones of said frame members, a pair of electrical contacts for relative movement by said armature between engaged and disengaged relative positions, and electromagnetic means comprising a tubular bobbin positioned about said mounting member and armature and a pair of electromagnetic windings on said bobbin individually energizable for opposite polarization of said armature to thereby control the position to which said armature is magnetically attracted and the relative position of said contacts.

4. A latching relay comprising in combination, a mounting member, a pair of magnetic frame members fixed to said mounting member in spaced relation, a permanent magnet interposed between said frame members to oppositely magnetically polarize said members, a magnetically permeable armature pivotally mounted on said mounting member for movement alternatively to attracted positions with said frame members, a pair of electrical contacts for relative movement by said armature between engaged and disengaged relative positions, and electromagnetic means comprising at least one electromagnetic winding about said mounting member and armature for opposite polarization of said armature to thereby control the position to which said armature is magnetically attracted and the relative position of said contacts.

5. A latching relay comprising in combination, a magnetically impermeable mounting member, a pair of spaced magnetic frame members, :a permanent magnet interposed between said frame members to oppositely magnetically polarize said members, a magnetically permeable armature pivotally mounted on said mounting member having a portion to be alternatively attracted to opposite ones of said frame member, a pair of electrical contacts for relative movement by said armature between engaged and disengaged relative positions, and electromagnetic means comprising a tubular bobbin positioned about said mounting member and armature and at least one electromagnetic winding on said bobbin energizable for opposite polarization of said armature to thereby control the position to which said armature is magnetically attached and the relative position of said contacts.

6. An electromagnetic actuator comprising in combination, and elongated magnetically impermeable mounting member having opposite end portions, a pair of elongated magnetic frame members each of which is formed with a pair of depending opposite end portions fixed to the opposite end portions of said mounting member to provide a unitary structure therewith and at intermediate portion spaced from said mounting member, at least one permanent magnet interposed between said frame members to oppositely magnetically polarize them, a magnetically permeable armature movably mounted on said frame to be alternatively attracted to said frame members, and electromagnetic means for reversely polarizing said armature to thereby control the position to which said armature is attracted comprising an electromagnetic winding about said mounting member and armature thereon substantially filling the space between the opposite end portions of said frame members and between the mounting member with armature thereon and said intermediate portions of said frame members.

7. An electromagnetic actuator according to claim 6 wherein at least one of said depending end portions of one of said frame members is positioned in opposed spaced relation to one of said depending end portions of the other frame member, and said permanent magnet is interposed therebetween to oppositely polarize said frame members.

8. An electromagnetic actuator according to claim 6 wherein said frame members are aligned on said mounting member to cause each depending end portion of each frame member to be in opposed spaced relation to a separate one of the depending end portions of the other frame member, and a permanent magnet is POSltlOned between each pair of opposed end portions to magnetically polarize said frame members.

9. An electromagnetic actuator according to cla1m 8 wherein said armature is pivotally mounted on said mounting member and is provided with oppositely disposed pole portions for cooperation lndividually with a separate one of said pairs of opposed depending end portions of said frames whereby one of said pole portions is attracted to an end portion of one 9f said frame members while the other pole portion is 9 10 attracted to an end portion of the other of said frame 2,238,913 4/41 Miller 200-93 X members. 2,252,761 8/41 Estes 200-93 2,816,190 12/57 Peterson 20093 References Cied by the Examiner 3,030,469 4/62 L ich 200 93 X UNITED STATES PATENTS 5 3,041,422 6/62 Greshel 200-93 X 1675919 7/28 Babcock 317 172 3,168,628 2/65 Okamoto et a1. 200104 X 2,051,475 8/36 Grandstafi 200-93 BERNARD A. GILHEANY, Primary Examiner.

Claims (1)

1. AN ELECTROMAGNETIC ACTUATOR COMPRISING IN COMBINATION, A PAIR OF SPACED MAGNETIC FRAME MEMBERS, MAGNETIC MEANS INTEPOSED BETWEEN SAID FRAME MEMBERS TO OPPOSITELY MAGNETICALLY POLARIZE SAID MEMBERS, A MOUNTING MEMBER, AN ELONGATED ARMATURE PIVOTALLY MOUNTED ON SAID MOUTING MEMBER BETWEEN SAID FRAME MEMBERS HAVING OPPOSITE END PORTIONS INDIVIDUALLY ENGAGEABLE WITH SAID FRAME MEMBERS TO COMPLETE THE MAGNETIC CIRCUIT FOR SAID MAGNETIC MEANS, AND ELECTROMAGNETIC MEANS ON SAID ARMATURE COMPRISING A TUBULAR BOBBIN ABOUT SAID MOUNTING MEMBER AND ARMATURE AND AN ELECTROMAGNETIC WIND-

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