US 3414852 A
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Description (OCR text may contain errors)
Dec. 3, 1968 R. 1.. MARTIN 3,414,852
MAGNETIC LATCHING RELAY Filed April 27, 1967 2 Sheets-Sheet 1 1205527- 1;. MAeT/u INVENTOR.
BY 154211! 0AM Dec. 3, 1968 R. 1.. MARTIN 3,414,852
MAGNETIC LATCHING RELAY Filed April 27, 1967 2 Sheets-Sheet 2,
64 HOSEET 1,. MfiQT/N F INVENTOR.
38 63 BY 4o 42 I 5 M a/WV United States Patent 3,414,852 MAGNETIC LATCHING RELAY Robert L. Martin, La Canada, Calif., assignor to Consolidated Electronics Industries Corp., New York, N.Y., a corporation of Delaware Continuation-impart of application Ser. No. 513,908, Dec. 13, 1965. This application Apr. 27, 1967, Ser. No. 634,144
7 Claims. (Cl. 335-170) ABSTRACT OF THE DISCLOSURE A bi-stable, switching device that is capable of alternate'ly positioning a movable contact against one or another of two fixed contacts. Motion of the movable contact is controlled by energizing one or another of two coils with direct current to position the movable contact against the fixed contact which cooperates with the energized coil, while the other coil remains deenergized. When the movable contact has completed its movement to the fixed contact the coil is de-energized and the movable contact will remain held or latched in the position referred to by the magnetic field induced by the permanent magnet elements where the air gap between the magnet and the movable contact is the smaller. When the latching is to be released, the other coil is energized. This will create a magnetic field stronger than the field created by the permanent magnet and the movable contact will shift to the opposite fixed contact.
The design of micro-miniature equipment has advanced very remarkably in recent years with the calls upon it placed by missile and space vehicle demands. Although technology has evolved many successful micro-miniature relays and switches with acceptable performance characteristics there continue to be other problems to be overcome. One of these is complexity of assemblies which increases the prospect of devices getting out of order. Another is high cost of devices which, especially when somewhat complex, require a considerable amount of careful assembly and adjustment to operate dependably. Other shortcomings include a lack of desirable life span and insuflicient degree of precision especially when working with tolerances which need to be measured in a few thousandths of an inch, and frequently less.
Applicants copending application Ser. No. 513,908, filed Dec. 13, 1965, now Patent No. 3,335,376, of which this is a continuation-in-part, discloses a satisfactory structure suitable for micro-miniature use wherein a dependable procedure is revealed making it possible to construct a switching arrangement with stationary or fixed contacts anchored in position by the initial tooling operation and which makes use of an axially located tiltably mounted armature positively constructed to extremely low tolerances and adapted to operate between the two fixed contacts.
Another of applicants copending applications Ser. No. 633,289 filed Apr. 24, 1967, discloses a very acceptable method for assembling devices of the character disclosed by appropriate tooling so that no subsequent adjustment is either necessary or possible.
It is among the objects of the invention herein disclosed to provide a new and improved magnetic latching relay of comparable construction readily adapted to subminiature proportions and wherein a movable armature is independent of spring action for its operation.
Another object of the invention is to provide a new and improved magnetic latching relay which makes use of magnetic fields set up by permanent magnets as a latching medium for holding a movable armature in one position or another.
Still another object of the invention is to provide a new and improved magnetic latching relay making use of permanent magnets for the latching operation which employs a relative minimum number of moving parts, which is simple in construction thereby lending itself to a very simple assembly procedure made possible by simple and inexpensive tooling, which is easily varied in size and proportion to meet different demands, capabilities, current load, etc., which is of inexpensive construction and which can be produced from relatively inexpensive materials.
With these and other objects in view, the invention consists of the construction, arrangement, and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.
In these drawings:
FIGURE 1 is a side perspective view of the device abundantly broken away to show the relationship of the various parts;
FIGURE 2 is an exploded perspective view to better reveal the form, size and relationship of parts;
FIGURE 3 is a longitudinal sectional view through the device showing the armature in a position such that the movable contact is in engagement with one of the fixed contacts;
FIGURE 4 is a longitudinal sectional view on the line 44 of FIGURE 3;
FIGURE 5 is a cross-sectional view on the line 5-5 of FIGURE 3;
FIGURE 6 is a cross-sectional view on the line 66 .of FIGURE 3;
FIGURE 7 is a fragmentary cross-sectional view on the line 7-7 of FIGURE 3; and
FIGURE 8 is a fragmentary longitudinal sectional view on the line 88 of FIGURE 3.
In an embodiment of the invention which has been chosen primarily for the purpose of illustrating the principle involved herein there is shown a magnetic (latching relay consisting in the main of an operating assembly indicated generally by the reference character 10 lodged within a substantially cylindrical housing 11 having one closed end 12 and having at the opposite end a header 13. The header serves as a support for a series of pins or soldering posts some of which are shown in FIGURES 1, 2, 3 and 4 identified by the reference characters 14, 15, 16, and 17. In the device here under consideration two separate coil members and 21 are disclosed each constructed in substantially the same fashion. The coil member 20 consists of opposite annular discs 22 and 23 interconnected by a sleeve 24, and within which is wound a substantially conventional coil 25. The coil member 21 is similarly constructed of spaced annular discs 26 and 27 interconnected by means of a sleeve 28 and housing a coil 29. Appropriate wrappings 30 and 31 surround the coils.
At the inner end of the housing 11 the sleeve 24 projects slightly to form opposite spaced arcuate segments 32 and 33 which serve to position a somewhat arcuate semicircular magnetic plate 34. There are recesses 35 and 36 which receive respectively the segments 32 and 33 and intermediate the recesses is a pole face 37.
At the opposite or outer end of the housing 11 is a similar substantially arcuate semicircular magnetic plate 38 comprehending recesses 39 and 40 which receive respective segments 41 and 42 which are extensions of the sleeve 28. Here also there is a pole face 43 spanning the distance between the two recesses 39 and 40.
Intermediate the coil members 20 and 21 is a pair of magnetic sectors 44 and 45 which comprise a permanent magnet member. The magnetic plates 34 and 38 are soft iron magnetic material.
Within the sleeve 24 is a passage 46 which is in axial alignment with a similar passage 47 through the sleeve 28. For mounting an armature 50 in the combined passages 46, 47, there is provided a bushing 51 in which lateral openings 52 and 53, which admit inner ends of the respective magnetic sectors 44 and 45, are clearly shown in FIGURES 1, 2, 3 and 6. The armature 50 is pivotedly mounted upon the bushing 51 by means of a pivot pin 54 which rotates in holes 56 and 57. A positioning strap 58 fastened to the bushing 51 has an end 59 which overlies the disc 22 at the inner end of the housing thereby to hold the bushing in proper position, and accordingly properly position and mount the armature 50, so that it can reciprocate laterally within the passages 46 and 47.
A stationary support indicated generally by the reference character 60, of appropriate dielectric material, is secured in a position adjacent the header 13 by mounting it as shown on the outside face of the magnetic plate 38. The stationary support 60 is annular in shape as readily appears in FIGURE 2 and is provided with a central opening 61 of ample diameter. Fixed contacts 62 and 63 are anchored in the stationary support 60 in positions extending into the central opening 61. In the embodiment shown the fixed contacts are substantially cylindrical rods which are embedded initially in position by use of an appropriate fixture which provides a precise spacing between adjacent edges of the contacts. A movable contact 64 is provided on the outer end of the armature 50, preferably coined to give it a precise dimension and more particularly a precise transverse size measured in the direction between the fixed contacts 62 and 63, as best seen in FIGURE 3. A flexible pigtail 65 connects the movable contact 64 with one of the pins 16. Similar pigtails 66 and 67, suggested schematically in FIGURE 3, connect the movable contacts 62 and 63 with respective pins 15 and 17. Other pins are provided for attachment of opposite ends of wires from the coils 20 and 21, not shown in the interest of clarity.
To complete the structure of the operating assembly 10, there is provided a magnetic sleeve 70 which surrounds the exterior of both of the coil members 20 and 21 and which also overlies outside edges of the magnetic plates 34 and 38 and also the outside edges of the magnetic sectors 44 and 45. The magnetic sleeve accordingly completes the magnetic paths for the permanent magnet elements and also assists in holding the coil members and related parts in a compact unitary operating assembly. An insulating jacket 71 extends over the entire exterior of the magnetic sleeve.
In operation the permanent magnet elements serve to induce continuous magnetic fields through two closed loop magnetic paths. One path consists of the inner magnetic plate 34, the adjacent portion of the magnetic sleeve 70, the magnetic sectors 44 and 45 and the adjacent portion of the armature 50. The other magnetic path is formed by the outer magnetic plate 38, the adjacent portion of the magnetic sleeve 70, the magnetic sectors 44 and 45 and the adjacent portion of the armature 50. The armature 50 is thus simultaneously attracted to both magnetic plates by magnetic forces of intensities inversely proportioned to air gap distances of respective air gaps 72 and 73. In the position of adjustment of FIGURE 3 it will be noted that the air gap 72 is larger than the air gap 73. When the armature 50 has been actuated by energizing the coil 29 the movable contact 64 will be pivoted or swung to a position of engagement with the fixed contact 62 as shown in FIGURES 3 and 7, because the intensity of the magnetic field created by excitation of the coil 29 is substantially greater than any magnetic field generated by the permanent magnetic loops. In this position, however, the attraction of the magnetic plate 38 will be greater than the attraction of the magnetic plate 34 so that when 4 the coil 29 is de-energized the armature 50 will be held or latched in position against the fixed contact 62.
After the armature has been latched as just described should the coil 25 be energized, the magnetic field thus created will be sufiiciently great to overcome the magnetic attraction of the permanent magnetic loops and will cause the armature 50 to pivot counterclockwise in an opposite direction until the movable contact 64 is pulled into engagement with the fixed contact 63. When this happens the size of the air gaps 72 and 73 will be reversed, the air gap 72 becoming smaller and the air gap 73 becoming larger. Consequently when the coil 25 is de-energized the movable contact 64 will be held or latched in a position of engagement with the fixed contact 63 by reason of the greater attraction of the magnetic loop formed by the magnetic plate 34 in contrast with the weaker magnetic loop of the magnetic plate 38. This position of course can be immediately changed by re-energizing the coil 29 which will reciprocate motion of the armature 50 and again draw the movable contact 64 into engagement with the fixed contact 62. The relay may be repeatedly cycled in the manner described by alternately and individually energizing and de-energizing the coils 25 and 29 with direct current.
While the invention has herein been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.
Having described the invention, what is claimed as new in support of Letters Patent is:
1. A magnetic latching relay for an electric circuit comprising an operating assembly having opposite ends, a coil form including a plurality of longitudinally spaced coils located between opposite ends, a permanent magnet member located between said coils, and a magnetic plate on the outer side of each coil, a stationary support in said assembly adjacent one end and a pair of transversely spaced fixed contacts mounted on said support, said coil form having an open axial passage therethrough, an armature in said passage mounted for reciprocating movement in said assembly, whereby opposite ends of said armature are adapted to change their respective positions, one end of said armature having a movable contact located intermediate said fixed contacts, said movable contact when in engagement with one of said fixed contacts upon energization of one of said coils forming air gaps of different distances between opposite ends of said armature and the respective magnetic plates, said different distances being reversed in relative magnitude when the movable contact is in engagement with the other fixed contact upon de-energization of said one coil and energization of the other coil, whereby when one of the coils has been energized the armature is shifted to a corresponding position and latched temporarily by permanent magnetic attraction in said last position after the coil is de-energized.
2. A magnetic latching relay as in claim 1 wherein there is a magnetic sleeve surrounding said coils, said magnetic plate and said permanent magnetic member which completes the magnetic path.
3. A magnetic latching relay as in claim 1 wherein the fixed contacts are anchored in non-adjustable position in said support and the armature is free of engagement with the magnetic plate in all positions of the armature.
4. A magnetic latching relay as in claim 1 wherein the magnetic plates are substantially arcuate in form and have each a central open area surrounding the respective end of the armature. I
5. A magnetic latching relay as in claim 1 wherein the permanent magnet member comprises a pair of substantially sector shaped relatively fiat elements spaced opposite each other on respectively opposite sides of said passage.
6. A magnetic latching relay as in claim 1 wherein a bushing provides a carrier for said pivotal mounting of the armature, said bus-hing being shorter than said passage and having portions on opposite sides of said permanent magnet member engaging said coil form within said passage.
7. A magnetic latching relay as in claim 1 wherein there is a housing surrounding said assembly and a header at one end of the assembly having electric contact posts thereon connected to said respective movable and fixed contacts.
6 References Cited UNITED STATES PATENTS 9/1961 Didier 335-470 8/1965 Kramer 335-254 BERNARD A. GILHEANY, Primary Examiner.
H. BROOME, Assistant Examiner.