US3161749A

US3161749A - Vacuum relay

Info

Publication number: US3161749A
Application number: US190927A
Authority: US
Inventors: John T Perry; Chester J Kawiecki
Original assignee: Joslyn Manufacturing and Supply Co
Current assignee: Joslyn Manufacturing and Supply Co
Priority date: 1962-04-30
Filing date: 1962-04-30
Publication date: 1964-12-15
Anticipated expiration: 1981-12-15

Description

Dec. 15, 1964 J PERRY ETAL 3,161,749

VACUUM RELAY Filed April 30, 1962 //V|/E/V70R$.

JOHN T. PERRY CHESTER J. KAWIECKI BY BUCK HORN, CHE A THAM a BLORE A T TORNE YS United States Patent 3,161,749 VACUUM RELAY John T. Perry, Bellwood, and Chester J. Kawiecki, Chicago, Ill., assignors to Zioslyn Manufacturing and Supply (30., Chicago, lill., a corporation of Illinois Filed Apr. 30, 1962, Ser. No. 190,927 8 Claims. (Cl. 280-144) The present invention relates to electrical devices and more particularly to vacuum relays.

An object of the present invention is to provide a new and improved vacuum relay.

Another object of the present invention is to provide a vacuum relay capable of operating at relatively high currentand voltage loads.

Still another object of the present invention is to provide a relay having relatively low internal reactance.

A further object of the invention is to provide a relay that may be manufactured at a relatively low cost.

Another object of the present invention is to provide a relay having a minimum of moving parts and which may be operated a maximum number of times without failure.

Still another object of the present invention is to provide a relay construction that permits of easy and ready manufacture and assembly of the parts thereof.

A further object of the invention is to provide an extremely rugged design capable of withstanding severe vibration and shock conditions.

Still other objects and advantages of the present invention will becomemore apparent hereinafter.

The illustrated embodiment of the present invention comprises a four-pole, double throw relay though it will be apparent that the principles of the relay can be adapted to a single-pole, single throw type or other pole and throw arrangement. The illustrated relay comprises a glass envelope which forms a support for the contact elements each of which extends through the envelope to provide for electrical connection thereto. A plurality of movable contact elements are provided each of which includes a plate-like strip of suitable material such as molybdenum supported at one end and which may be flexed axially of the envelopeto make or break engagement with a fixed contact element. The movable contact elements are engaged in their free ends in an insulating rod, axial movement of which causes switching movement of the movable contacts. The rod is mounted upon a bellows fixed to an end plate closing the envelope. The bellows is secured to a magnetic disc with which a coil is associated to pull bellows outwardly upon energization of the coil so as to eifect movement of the rod and movable contacts in the corresponding direction. Upon de-energization of the coil the external air pressure upon the same causes bellows and rod and contacts to move therewith in the opposite direction.

For a more detailed description of the invention reference is made to the accompanying drawings and the following detailed description.

In the drawings:

FIG. 1 is a longitudinal section of a relay made in accordance with the invention;

FIG; 2 is a sectional view taken along line 2-2 of FIG. 1; and

FIG. 3 is a sectional view taken along line 3--3 of FIG. 1.

To illustrate the invention there is shown in the drawing a relay comprising an evacuated envelope including a dielectric bulb havingva tubular or cylindrical wall portion 12. The bulb may be made of any suitable material and preferably it is made of a glass having characteristics which will permit ready sealing of the glass 3,161,749 Patented Dec. l5, 1964 to the various metallic elements that have to be connected thereto. The wall portion 12 is connected at its lower end through a glass-to-metal seal to a ring 14, preferably of molybdenum, which is in turn brazed or welded to a flange 16 which may be formed of Monel metal. The flange 16 is brazed or welded to a Monel ring 18 supporting a cup-like housing 20 which may also be of Monel. The flange 16, ring 18 and housing 20 define in effect an end wall for the. evacuated envelope.

The upper end portion 22 of the housing is of a re duced diameter and is provided in the end wall 24 thereof with an opening 26 through which may slide the supporting stem 28 of a switch actuator member or rod to be described in greater detail hereinafter. The lower end of the stem 28 is secured to a cylindrical plate or element 30 of soft iron or other suitable magnetic material. Extending between the end wall 24 and the plate 30 and hermetically sealed to both is a bellows 32 which will permit axial movement of the stem 28 and plate 30. A flange 34 may be provided on the stem 28 to limit the upward movement of the stem upon engagement with the wall 24.

Mounted within the lower portion of the housing 20 is an actuating mechanism comprising a coil assembly H including an iron shell and a core 42 mounted on an end plate 44. The core 42 is surrounded by a coil indicated at 46. As will be apparent, the core 42, end plate 44, shell 40 and plate '30 form a magnetic circuit. The shell 40 and other portions of the actuating mechanism are removably secured within the housing 20 by means of a snap ring 48 fitting within a groove in a tubular extension 56 ofthe housing 20. External threads 52 may be provided on the extension for mounting of the relay.

Fixed to and extending upwardly from the stem 28 is an actuator rod 60 preferably formed of a non-conductive ceramic and which, as may be seen in FIG. 3, is oblong in cross section but symmetrical about its axis, the axis of the rod 64) being coincident with the axis of the bulb iii. The opposite narrow edges of the rod 60 are provided with two pairs of opposite, co-planar, axially perpendicular,

transverse slots

62, 64 and 66, 68.

Hermetically sealed in the bulb 10 are a plurality of

movable contacts

71, 72, 73 and 74 which include rigid, rod-like supporting ;means or

posts

75, 76, 77 and 78, respectively, which extend outwardly of the bulb 10 through the sidewall thereof. Fixed in the .end of the posts are thin, plate-

like switching elements

82, 84; 86, 88 which are perpendicular to the actuator axis and the distal ends of which extend into the slots 62, 64, 66 and68,.respectively. Such slots have a height somewhat greater than the thickness of the switching ele-' ments, as best shown in FIG. 1, to permit sliding of such elements in and out of the slots as the rod moves axially. The switching elements preferably are formed of molybdenum or similar material having sufficient flexibility for the purpose to become apparent and the posts are formed of tungsten. As will be apparent, vertical movement of the actuator rod 60 will cause corresponding flexing of the elements 82-88.

As shown, the switching elements are arranged in two opposing pairs, the element 84 being opposite the element 82 and theelement 86 opposite the" element 88, the elements 84, 86 being alignedaxially of the bulb as are the

elements

82, 88. Fora purpose to be explained the opposed elements are spaced from one another by a distance slightlyg'reater than the thickness of the actuator cylindrical'tungsten rods, one of the contacts 92 extending above and the other contact 94 extending below the switch element 82 (see FIG. 2), the axes of the contacts being substantially parallel to planes normal to the actuator rod 60 and to the switch element 82. The

contacts

92, 84 are spaced apart a slight distance vertically, the spacing being greater than the thickness of the element 82, and they each extend outwardly of the bulb so as to permit electrical connections to be made thereto.

The contact 92 is so positioned with relation to the switch element 82; that the latter will engage the contact 92 when the flange 34 of the actuator rod stem 28 engages the housing end wall 24. When the contacts are so engaged, an electrical circuit between contact 92 and contact 71 is closed. The contact 94 is positioned so that it will be engaged by the switching element 82 as the latter is moved downwardly by movement of the magnetic element 30 on the lower end of the stem 28 into engagement with the armature 42. This latter action will occur, of course, when the magnet coil 46 is energized. Engagement of the switching element 82 with the contact 94 will close a circuit through the

contacts

71, 94. Upon de-energization of the coil 46 the external air pressure acting upon the plate 30 and diaphragm 32 will move the actuator rod 60 upwardly to return the switch element 82 to the position shown in FIG. 1 in engagement with the contact 92 thus opening the circuit through

contacts

71, 94 and reclosing a circuit through

contacts

71, 92. Thus, as is apparent, switching will occur by alternate energization and de-energization of the coil 46.

Similarily arranged with the

switch elements

84, 86 and 88 are other pairs of electrodes or contacts indicated generally by the reference numeral 100. While the illustrated relay is of a four pole, double throw type it will be obvious that the arrangement of the invention is adapted to other types of relays. As will be apparent from FIG. 3, the fixed contacts extend angularly across the flexible contacts and outwardly of the envelope at points spaced circuferentially from the movable contacts so that a relatively long path exists between such electrodes thus minimizing the possibility of a breakdown occurring along the surface of the envelope between electrodes.

In assembling the relay of the invention the bulb 10 is first prepared, the various electrical contacts sealed therein and the mounting ring 14 secured to the end of the bulb and the flange 16 brazed thereto. Since the portions of the electrical contacts extending through the bulb are of tungsten and the ring 14 is of molybdenum the bulb may be formed of a single type tungsten sealing glass such as Corning type 3320. Next the housing 20 is prepared with the flange 18 hermetically secured thereto and the bellows 32 mounted thereon with the actuator rod 60 mounted and secured upon the bellows. The housing 20 and actuator rod are then inserted within the bulb 10 with the actuator rod positioned so that it is rotated 90 with respect to its operative position, the latter position being shown in FIG. 3. Since the thick ness of the actuator rod is less than the distance between the ends of the opposing pairs, 82, 84 and 86, 88, of the switching elements the rod can be slipped upwardly into its operative vertical position and then rotated 90 so as to engage the movable contacts within the respective grooves 62-28. At that point the

flanges

16, 18 will be in contact and the same can be heliarc welded or otherwise suitably secured together so that the lower end of the envelope will be vacuum tight. Thereafter, the envelope can be evacuated through the tubulation in dicated at 98; and which is finally sealed off when the desired degree of evacuation is obtained. Finally the coil assembly can be inserted in the cavity provided and secured in place by the ring 48. As will be apparent the coil assembly may be easily and quickly replaced.

It will be observed that the switching elements 82-88 make a line engagement with the fixed contactsthereby 4.- minimizing contact resistance and the wattage loss within the device. A relay such as shown is capable of operating at loads of the order of 20,000 volts and 20 amperes. Inasmuch as the actuator rod assembly is relatively light in weight it has a relatively low inertia enabling fast response to energization or de-energization of the coil and contact chatter during the periods of vibration will be minimized.

Having illustrated and described a preferred embodiment of the invention, it should be apparent that the invention permits of modification in arrangement and detail. We claim all such modifications as come within the true spirit and scope of the appended claims.

We claim:

1. In avacuum relay,

an evacuated envelope including a dielectric bulb having a cylindrical wall portion,

means defining an end wall sealed to one end of said bulb,

said end wall having an opening therein coaxial with the axis of said cylindrical wall portion,

a bellows hermetically sealed at one end thereof to the outer surface of said end wall about said opening,

said bellows being positioned outwardly of said wall,

a circular magnetic plate sealed to and closing the opposite end of said bellows,

a rigid fixed contact mounted in said bulb,

a movable contact mounted in said bulb for movement into and out of engagement with said fixed contact,

an actuator rod operatively connecting said movable contact to said magnetic plate,

magnetic means mounted on said end wall for moving said magnetic plate including a core mounted adjacent said magnetic plate, and adapted upon energization to move said plate outwardly, a'coil surrounding said core for energizing said core, and a housing of magnetic material surrounding said core and coil.

2. In a vacuum relay,

a tubular dielectric bulb,

an actuator rod mounted coaxially in said bulb for movement in the axial direction,

said actuator rod comprising a dielectric portion of oblong configuration in cross section and symmetrical about said axis, said rod portion having a pair of coplanar, axially perpendicular transverse slots in the opposite narrower ends thereof,

a pair of diametric movable contact elements each having an end portion received one in each of said slots, electrically conductive means fixedly supporting the gpplpsing ends of said contact elements from said the opposing ends of said contact elements being spaced apart a distance no less than the lesser width of said actuator rod portion whereby said rod may be disengaged from said contacts by rotating the rod about its axis.

3. In a vacuum relay,

an envelope including a dielectric bulb having a cylindrical wall portion,

means defining an end wall sealed to one end of said bulb,

a bellows hermetically sealed at one end thereof to the outer. surfaceof said end wall about said opening, said bellows being positioned outwardly of said wall, a circular magnetic plate sealed to and closing the opposite end of said bellows,

a fixed contact mounted in said bulb,

a movable contact mounted in said bulb for movement axially of said bulb into and out of engagement with said fixed contact, I

each of said contacts including a portion sealed in said bulb and extending outwardly thereof and forming an electrical connection for said contacts,

and magnetic means operatively arranged with said magnetic plate for efiecting outward movement of said magnetic plate.

4. A vacuum relay comprising:

an envelope including a'dielectric bulb having a cylindrical wall portion,

an actuator housing sealed to one end of said Wall portion, and defining an end wall,

said housing end wall having .an opening therein coaxial with the axis of said cylindrical wall portion,

a bellows hermetically sealed at one'end thereof to the outer surface of said end wall about said opening extending outwardly of said wall,

a magnetic plate sealed to the opposite end of said bellows,

a movable contact mounted on said bulb wall portion and having a portion extending exteriorly of the envelope to permit electrical connection thereto,

said movable contact comprising a mounting portion mounted in fixed position in said bulb and a flexible, plate-like element extending from said mounting portion and capable of flexing in the axial direction of said bulb,

a pair of rigid, fixed contacts mounted on said bulbwall portion with one of said fixed contacts on each of the opposite sides of said movable contact element,

each of said fixed contacts extending outwardly of said bulb and constituting an electrical lead,

an actuator rod mounted on said magnetic plate and extending through said opening coaxially with said envelope wall portion,

said rod comprising a dielectric portion having a slot therein receiving the distal end of said movable contact,

and a magnetic coil mounted in said actuator housing in operative relation with said plate whereby upon energization of said coil, said plate is attracted thereto to move said rod axially thereby moving said movable contact in one direction and upon de-energization of said coil said plate is moved by external air pressure in the opposite direction thereby moving said movable contact in said opposite direction.

5. In a vacuum relay,

an envelope including a tubular dielectric bulb including an open end,

a fixed contact in said bulb,

a movable contact in said bulb,

an actuator element in said bulb movable axially thereof and operatively connected to said movable contact to effect movement thereof into and out of engagement with said fixed contact,

a wall member of non-magnetic material,

a tubular ring securing said wall member to said bulb end,

said wall member being reentrant and defining an outer cup-shaped housing coaxial with said bulb and opening outwardly with respect thereto and an inner, coaxial cup-shaped housing of smaller diameter than said outer housing, the inner end of said inner housing having a coaxial opening therein to the said bulb,

a bellows mounted coaxially in said inner housing, one end of said bellows being sealed to the edge of the said opening in the inner end of said housing,

a disc of magnetic material sealed to the opposite end of said bellows, said disc being substantially in the plane of the inner end of said outer housing,

said actuator element being secured to said disc whereby axial movement of said disc causes axial movement of said actuator element,

and magnet means for effecting outward movement of said disc,

said magnet means comprising a housing of magnetic material cylindrical in configuration fitting snugly within said outer housing, said magnet means housing having an inner end wall provided with a coaxial opening of a diameter just slightly greater than said disc whereby said disc may move freely within said opening axially thereof,

a coaxial magnetic core in said magnet means spaced axially from said disc and a coil surrounding said core, whereby upon energization of said coil said disc will be drawn outwardly relative to said bulb and upon deenergization of said coil the exterior air pressure upon said diaphragm will cause said disc to move inwardly relative to said bulb.

6. Ln a vacuum relay,

an envelope including a tubular bulb formed solely of dielectric material,

an actuator rod mounted in said bulb,

means operatively connected to said rod for effecting axial reciprocation thereof,

said rod comprising a dielectric portion having an axially perpendicular slot in the periphery thereof,

a flexible, plate-like switching element of electrically conductive material having an end portion extending into said slot, 7

said slot being of slightly greater height than the thickness of said element whereby the latter may slide within said slot,

support means fixedly supporting the opposite end of said switching element from said bulb,

said support means comprising a rigid, rod-like post extending into said bulb through the sidewall thereof and sealed therein,

a rigid, fixed contact positioned adjacent said switching element for engagement and disengagement by said switching element as said actuator rod is reciprocated,

said fixed contact comprising a cylindrical rod the longitudinal axis of which is substantially parallel to the plane of said switching element,

said fixed contact rod extending outwardly of said bulb sidewall at a point spaced circumferentially from said support meansv 7. An electrical switch comprising an evacuated envelope including an elongated sidewall defining tubular dielectric portion,

an actuator member in said envelope mounted for movement in a direction parallel to the axis thereof,

means operatively connected to said actuator member for moving the same between two axially spaced positions,

a movable contact member including a rigid, rod-like conductive mounting portion hermetically sealed in said sidewall defining dielectric portion and extending within and without said envelope,

said movable contact member including a flexible contact portion having one end fixed to said movable contact mounting portion,

said flexible contact portion being engaged by said actuator member at a point remote from said mounting portion so that axial movement of said actuator member causes corresponding axial movement of said flexible contact portion,

and a fixed contact comprising a rigid, rod-like member hermetically sealed in said sidewall defining dielectric portion at a point spaced circumferentially from said movable contact support portion and extending within and without said envelope,

said fixed contact extending angularly across said flexible contact portion within the limits of movement of said flexible contact portion so as to be engaged by said flexible contact portion in one position of said actuator member and so as to be spaced from 6 said flexible contact portion in the other position of said actuator member.

8. An electrical switch comprising an evacuated envelope including an elongated tubular sidewall defining dielectric portion,

a movable contact member including a rigid, rod-like conductive mounting portion hermetically sealed in said sidewall defining dielectric portion and extending within and without'said envelope,

said movable contact member including a flexible contact portion having one end fixed to said movable contact mounting portion and the other end engaged by said actuator member so that axial movement of said actuator member causes corresponding axial movement of said flexible contact portion,

said fixed contact extending angularly across said flexis ble contact portion between said actuator member and said mounting portion and within the limits of movement of said flexible contact portion so as to be engaged by said flexible contact portion in one position of said actuator member and so as to be spaced from said flexible contact portion in the other position of said actuator member.

References Cited in the file of this patent UNITED STATES PATENTS 2,886,668 Steward et al May 12, 1959 2,905,788 Harrison Sept. 22, 1959 2,908,780 Walters Oct. 13, 1959 2,938,092 Steward May 24, 1960

Claims

1. IN A VACUUM RELAY, AN EVACUATED ENVELOPE INCLUDING A DIELECTRIC BULB HAVING A CYLINDRICAL WALL PORTION, MEANS DEFINING AN END WALL SEALED TO ONE END OF SAID BULB, SAID END WALL HAVING AN OPENING THEREIN COAXIAL WITH THE AXIS OF SAID CYLINDRICAL WALL PORTION, A BELLOWS HERMETICALLY SEALED AT ONE END THEREOF TO THE OUTER SURFACE OF SAID END WALL ABOUT SAID OPENING, SAID BELLOWS BEING POSITIONED OUTWARDLY OF SAID WALL, A CIRCULAR MAGNETIC PLATE SEALED TO AND CLOSING THE OPPOSITE END OF SAID BELLOWS, A RIGID FIXED CONTACT MOUNTED IN SAID BULB, A MOVABLE CONTACT MOUNTED IN SAID BULB FOR MOVEMENT INTO AND OUT OF ENGAGEMENT WITH SAID FIXED CONTACT, AN ACTUATOR ROD OPERATIVELY CONNECTING SAID MOVABLE CONTACT TO SAID MAGNETIC PLATE, MAGNETIC MEANS MOUNTED ON SAID END WALL FOR MOVING SAID MAGNETIC PLATE INCLUDING A CORE MOUNTED ADJACENT SAID MAGNETIC PLATE, AND ADAPTED UPON ENERGIZATION TO MOVE SAID PLATE OUTWARDLY, A COIL SURROUNDING SAID CORE FOR ENERGIZING SAID CORE, AND A HOUSING OF MAGNETIC MATERIAL SURROUNDING SAID CORE AND COIL.