US3238324A

US3238324A - Miniature hermetically sealed relay

Info

Publication number: US3238324A
Application number: US238364A
Authority: US
Inventors: Clark T Roessler
Original assignee: Jennings Radio Manufacturing Corp
Current assignee: Jennings Radio Manufacturing Corp
Priority date: 1962-11-19
Filing date: 1962-11-19
Publication date: 1966-03-01
Anticipated expiration: 1983-03-01
Also published as: BE669075A

Description

March 1, 1966 c. T. ROESSLER MINIATURE HERMETICALLY SEALED RELAY Filed Nov. 19, 1962 INVENTOR. CLARK T. ROESSLER AGENT United States Patent 3,238,324 MINIATURE HERMETICALLY SEALED RELAY Clark T. Roessler, San Jose, Calif, assignor to Jennings Radio Manufacturing Corporation, San Jose, Calif, a corporation of Delaware Filed Nov. 19, 1962, Ser. No. 238,364 Claims. (Cl. 20087) This invention relates to electric relays, and particularly to a miniature relay embodying an hermetically sealed housing.

The advent of missiles, space vehicles, and jet aircraft has created the need for a relatively high voltage, high frequency electric relay of rugged construction for airborne radio transmitting equipment. Accordingly, it is one of the principal objects of the invention to provide a miniature, highly reliable, vibration-free relay having the capability of operating at approximately two kilovolts at sixteen megacycles, while carrying up to approxmately seven amperes of current.

Because of the relatively high radio frequencies utilized with air-borne radio equipment, it is necessary that relays used in communication circuits be fast operating. It is therefore another object of the invention to provide a relay capable of operating in one millisecond.

Since reliability is an important factor in the use of relays in airborne equipment, and since enclosing relay contacts within an hermetically sealed housing having a controlled atmosphere or no atmosphere, i.e., a vacuum, increases the reliability, it is another object of the present invention to provide a miniature relay in which the contact points are enclosed within an hermetically sealed housing.

The ability of a relay to withstand impact shocks and high acceleration and deceleration forces is determined to a large extent by the nature and mounting of movable parts in the relay. It is therefore another object of the invention to provide a relay capable of withstanding such forces to at least 10Gs at vibration levels of 1000 cycles per second.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will become apparent from the following description and the drawings. It is to be understood however that the invention is not limited by the description and the drawing, as it may be embodied in various forms within the scope of the appended claims. Broadly considered, the relay of the invention comprises a hollow housing having opposed shell-like wall portions on one of which are mounted a plurality of terminals leads, portions of which extend into the housing. On the other shell-like wall portion is mounted a suitable actuating mechanism to effect make and break operation of a mobile contact mounted within the housing in a manner to selectively make or break a circuit through one of a plurality of fixed contacts and an adjacent terminal lead common to both fixed contacts. Suitable means associated with the mobile contact provide a resilient spring loading on the mobile contact tending to eliminate vibration thereof.

Referring to the drawings:

FIG. 1 is an elevation of the relay, a portion being broken away to reveal the interior construction.

FIG. 2 is a plan view of the relay illustrated in FIG. 1.

FIG. 3 is a vertical cross-sectional view taken in the plane indicated by the line 3-3 in FIG. 1.

FIG. 4 is a View of the interior of one of the shell-like wall portions in the direction indicated by the arrows on line 44 of FIG. 1 and illustrating the cooperative relationship between fixed and mobile contacts.

FIG. 5 is a view similar to FIG. 4 but taken in the Opposite direction and illustrating the actuating mechanism contained within the interior of the other shell-like housing portion.

FIG. 6 is a fragmentary view illustrating the assembled and at-rest relationship of fixed and mobile contacts. The view is taken in the direction of the arrow 6 in FIG. 4.

All of the figures are drawn approximately three times actual size.

In terms of greater detail, the miniature relay comprises a metallic housing designated generally by the numeral 2, and including a first or upper shell-like portion 3 and a second or lower shell-like portion 4, the shell-like portions being provided with radially outwardly extending peripheral flanges 5 and 6, respectively, adapted to be abutted as shown and hermetically bonded.

Shell portion 3 is provided with a wall 7 through which extend a plurality of substantially identical tubular terminal leads 8, each of the terminal leads being provided with relatively thin and thick wall sections 9 and 12, the thin wall section 9 being surrounded and hermetically bonded as by brazing within tubular dielectric bushing or spacer 13, preferably of ceramic.

The outer periphery of each bushing is hermetically bonded in an appropriate aperture formed in wall 7. It will thus be seen that the tubular dielectric bushing rigidly supports each terminal lead on the housing and electrically insulates each terminal lead from the associated shell portion when the shell portion is fabricated from metallic material as indicated in the drawing. It will of course be understood that the shell portion 3 can be fabricated from a dielectric material, such as ceramic, in which case the dielectric bushing would be eliminated and each terminal lead bonded directly to the dielectric shell. The portion of each terminal lead portion outside the housing beyond the associated dielectric bushing provides for connection of the relay into a circuit, while the terminal lead portions within the housing are utilized to support cooperatively related fixed and mobile contacts.

As shown in FIGS. 1, 3 and 4, two of the spaced and electrically insulated terminal leads are utilized to support a pair of rigid, plate-like

conductive contact members

16 and 17, each of which is supported on an associated terminal lead. The fixed contact plates are provided with mutually extending but spaced free-

end portions

18 and 19, respectively, each free-end portion being angularly disposed to the main body portion of the fixed contact plate. The fixed contact plates are arranged in planar alignment, and each plate hermetically seals the inner end of the associated terminal lead.

The inner end of the remaining terminal lead is hermetically sealed by a conductive mounting plate 21 to which is fixed, as by riveting, one end 22 of a resilient T-shaped strap-like mobile contact 23, the stem of the T-shaped strap extending transversely across the housing toward the spaced fixed contact plates. On its free end the stem is bifurcated to provide resilient finger-like por- 3

tions

24 and 26, the finger-like portion 24 being associated with fixed contact plate 16, and the resilient fingerlike portion 26 being associated with the fixed contact 17.

As shown best in FIGS. 4 and 6, the fixed contact plates are in planar alignment, while the resilient finger-

like portions

24 and 26 of the mobile contact are offset one from the other so as to make contact with remote sides of adjacent fixed contacts. The mobile contact is preferably fabricated from beryllium copper sheet preferably having a thickness of approximately .005, while the fixed contact plates are preferably fabricated from substantially thicker oxygen free high conductive copper plate. To illustrate the small size of the unit, it is noted that the resilient finger-

like portions

24 and 26 of the mobile contact are offset only .043". This much of an offset provides approximately .008" of gap between each fixed contact and the associated resilient finger-

like portion

24 or 26 when in the open position. The mobile contact, because of its strap-like nature and the proportions of the parts possesses inherent resiliency contributing from a .003" to .005" of overtravel. The structure may of course be scaled up or down.

To actuate the relay a remotely controllable solenoid designated generally by the numeral 31 is provided securely mounted on wall section 32'of shell 4; The solenoid includes a magnetic housing 33 the inner end of which projects into the housing and is hermetically sealed by a transverse ferromagnetic wall 34 brazed about its outer periphery Within the solenoid housing and'having brazed within its inner periphery a magnetizable core 36. Core and housing are coaxially arranged to provide an annular space therebetween within which is detachably mounted a suitable coil 37. End cap 38 secured to the threaded end portion of the core retains the coil within the housing and completes the magnetic circuit around this end of the housing.

At its inner end the low reluctance housing is provided with a ferromagnetic armature 39 resiliently hinged on the inner end of the housing by a spring 41, one end of which engages the armature and the other end of which is secured to the housing through a suitable mounting pad 42. The spring is preferably biased to urge the armature toward the adjacent T-shaped mobile contact.

As best seen in FIGS. 3 and 5, the armature is provided with an aperture 43 chamfered as shown to receive a spherical dielectric thrust or electrically insulating member 44. The parts are proportioned so that the sphere abuts the underside of mobile contact 23 when resting in the chamfered aperture, thus exertlng a resillent force thereagainst to displace the mobile contact in a direction to make a circuit through resilient finger-like portion 24 and fixed contact 16. In the embodlment illustrated this resilient force is provided by leaf spring 41, but it will of course be understood that other types of spring means may be utilized.

Opposing the resilient forces exerted by the armature through the dielectric sphere is the inherent res1l1ency of the strap-like mobile contact in its tendency to be displaced downwardly as seen in FIG. 3 so as to make a circuit between the resilient finger-like portion 26 and the fixed contact 17. It will thus be seen that these two oppositely directed resilient forces maintam a constant and resilient load on the mobile contact and armature, thus enabling the mechanism to withstand high values of acceleration, deceleration, impact shock and vibration.

To operate the relay to make or break a circuit the coil is provided with

appropriate terminals

46 and 47 to energize the coil and complete a magnetic circuit through the armature to pull the armature against the inner end of the core. When this occurs the dielectric sphere is pulled away from the mobile contact which, because of its inherent resilience, follows the sphere downwardly until the mobile contact is suspended on resilient-like portion 26. In this position of theparts the dielectric sphere remains in the aperture provided to receive it and thus in either position of the mobile contact the actuating assembly is electrically insulated from the mobile contact.

The embodiment of the relay illustrated utilizes an evacuated housing provided with a suitable tubulation 48, but it is to be understood however that instead of being evacuated the housing may be charged with a suitable gas.

I claim:

1. A relay comprising a housing, a plurality of terminal leads extending into and supported on the housing to provide inner and outer spaced terminal ends, a plurality of fixed contacts within the housing on the inner terminal ends of at least two of the terminal leads, a mobile contact supported within the housing on one of said inner spaced terminal ends and normally resiliently urged in a first direction tending to displace the mobile contact to make a circuit through a first one of the fixed contacts and an adjacent terminal lead including said inner spaced terminal end on which the mobile contact is supported, and an actuating assembly mounted on the housing and operatively connected to the mobile contact and normally resiliently urging the mobile contact in a second direction opposite to said first direction tending to displace the mobile contact to break a circuit through said first one of said fixed contacts and make a circuit through the second one of the fixed contacts and said adjacent terminal lead.

2. The relay according to claim 1, in which the force resiliently urging the mobile contact in said second direction is of a magnitude sufficient to overcome the force resiliently urging the mobile contact in said first dire-ction whereby the mobile contact is displaced to make a circuit through the second one of said fixed contacts.

3. The relay according to claim 1, in which the fixed contacts comprise rigid plate-like conductive members having mutually extending but spaced free-end portions providing fixed contact surfaces.

4. The relay according to claim 1, in which the mobile contact comprises a resilient strap-like member conductively connected at one end to one of the terminal leads and bifurcated at its other end adjacent the fixed contacts.

5. The relay according to claim 1, in which said housing comprises opposed shell portions having peripheral flanges adapted to be abutted and hermetically sealed.

6. The relay according to claim 1, in which the terminal leads comprise tubular metallic members having relatively thick and thin wall portions and the thin walled portions are hermetically united to the housing wall.

7. The relay according to claim 1, in which said actuating assembly comprises an electromagnetically operated solenoid including an armature within the housing resiliently urged in said second direction, and dielectric means interposed between the armature and the mobile contact electrically insulating the actuating assembly from the mobile contact.

8. In a relay including an hermetically sealed housing and terminal leads extending into the housing, a fixed and mobile contact assembly comprising a pair of rigid plate-like conductive members mounted on a pair of said terminal leads and extending substantially perpendicularly therefrom to provide fixed contact surfaces remote from said terminal leads, a mobile contact comprising a resilient strap-like member conductively connected at one end to one of said terminals and extending substantially perpendicularly therefrom between said pair of said terminals and providing a resilient strap-like portion movable to engage and disengage said fixed contact surfaces, and means on the housing to effect movement of the mobile contact.

9. The relay according to claim 8, in which said rigid conductive contact members are in planar alignment, said resilient strap-like portion of the mobile con- 5 tact is bifurcated toprovide space finger-like portions ofiset and movable to engage opposite sides of the adjacent plate-like conductive members.

10. The relay according to claim 8, in which said terminal leads are tubular and hermetically sealed at their ends Within the housing.

References Cited by the Examiner UNITED STATES PATENTS 1,905,751 4/1933 Rankin. 2,432,230 12/ 1947 Dorne 200153 2,810,026 10/1957 Vigren et a1 200-166 Leonard 200144 Sausser 200-153 Ducati 20087 Jennings 200-144 Charles 200-153 Jennings 200153 Jennings.

Dean 200-87 X Gregg 200-466 10 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.