US3316378A

US3316378A - Hermetic sealed switch

Info

Publication number: US3316378A
Application number: US450695A
Authority: US
Inventors: Thomas J Ryan
Original assignee: Texas Instruments Inc
Current assignee: Texas Instruments Inc
Priority date: 1965-04-26
Filing date: 1965-04-26
Publication date: 1967-04-25
Anticipated expiration: 1984-04-25

Description

April 25, 1967 Filed April 26, 1965 T. .1. RYAN 3,316,373

HERMETIC SEALED SWITCH 3 Sheets-Sheet l Tiwma' vfglyany T. J. RYAN April 25, 1967 HERMETIC SEALED SWITCH 5 Sheets-Sheet 2' Filed April 2G, 1965 jmvemar, ma; rlgz, Algen.

Tha @my United States Patent O Delaware Filed Apr. 26, 1965, Ser. No. 450,695 6 Claims. (Cl. 20G-16S) This invention relates to improvements in sealing means for electric switches and with regard to certain more specific features to electric toggle switches with hermetic sealing means.

Among the several objects of the invention may be noted the provision of a new and improved toggle seal with a negligible leak rate which is durable, long-lasting and which is relatively inexpensive to manufacture.

Another object of the invention is to provide a hermetic seal for a toggle mechanism which occupies a minimum amount of space.

Another object of the invention is the provision of a seal which is protected from external abuse.

Yet another object of the invention is the provision of a hermetically sealed terminal structure.

It is 'a further object of the invention to provide a sealed package of a device employing a toggle mechanism.

The invention accordingly comprises the elements and combination of elements, features of construction, and arrangment of parts which will be exemplified in the construction hereafter described, and the scope of which will be indicated in the following claims.

In the accompanying drawings, in which one of the various possible embodiments of the invention is illustrated,

FIGURE 1 Vis a cross-sectional view of the switch taken along lines 1-1 of FIGURE 2,

FIGURE 2 is Ia cross-sectional view taken along the lines 2 2 of FIGURE 1,

FIGURE 3 is a view similar to FIGURE 1 partly diagrammatic and partly in cross-section showing the contacts in alternative closed positions, and

FIGURE 4 is a view partly diagrammatic and partly in cross-section taken along the lines 4--4 of FIGURE 3.

Similar reference characters indicate corresponding parts through the several views of the drawings. Dimensions of certain of the parts, as shown in the accompanying drawings, have been modified for the purposes of clarity of illustration.

The sealing means of the instant invention is useful with any type of device which employs a pivotal type toggle arm, however, for the sake of completeness an exemplary embodiment is illustrated in the accompanying drawings which takes the form of a 2-pole, i-position, toggle switch generally indicated by reference numeral 10. A brief description will be given relating to the internal mechanism of this switch and the operation thereof, however, for further details, reference may be had to a co-pending `application Ser. No. 450,752, tiled Apr. 26, 1965 assigned to the assignee of the instant invention.

Referring now to the drawings, it will be noticed that a 2-pole switch has been illustrated (see FIGS. 2 and 4). The component parts of the two poles are identical and like parts in the two poles bear the same numerals. The two poles are electrically isolated by a web 44. The movable arm mechanism of one pole only will be explained,

lit being understood that the explanation applies in like manner to the other pole.

Barrier member 12 is made of a conventional electrically insulative material such as a phenolic resin and ice 14 is made of a conventional electrically insulative material such as a ceramic or a phenolic resin and is generally cup-shaped and forms a chamber in which the movable contact and toggle mechanism is located. Casing 14 is telescopically received in a complementary shaped conventional metal container 1S. Portions of the bottom wall of container 1S are conveniently turned inwardly to provide flanges 28 and apertures 26, which apertures receive the

terminals

20, 22 and 24 as explained infra. Cylindrical elements 30, each provided with bore 34, made of a suitable electrically insulative material such as a ceramic or a phenolic resin, are metallized in a conventional manner on the bottom face 32, the entire surface of bore 34 and the outside peripheral surface portion 36.

Terminal members

2G, 22 and 24 formed of a good electrically conductive material such as Monel are telescopically received within the cylindrical elements 30 and attached to the metallized bore thereof as by soldering. Each terminal member 2l), 22 and 24 is provided with an axially extending flange 38 which is attached as by soldering to face 32 of elements 30, which are inserted into mating apertures 15 provided in barrier 12, and flanges 28 of container 18 are then attached as by soldering to surface portions 36 on elements 30 to hermetically seal the terminal assembly. A conventional insulating potting `compound is used to ll in between elements 30 and barrier 12 as Well as between barrier 12 and container 18 to provide a protective enclosure for the terminal assembly.

Contact

buttons

21, 23 of silver or other good electrically conductive material are electrically fastened to terminals 2i) and 22 respectively, as at 19 although if desirable, the contacts and terminals may be of a one-piece construction.

Terminal members 2i?, 22, and 24 extend through apertures 42 provided in casing 14 as shown in FIG. 1. The bight of frame 54, which is generally U-shaped and formed of an electrically conductive material, is mounted on terminal 24 Which is headed over at 52. Frame 54 is provided with two

upstanding wall portions

56 and 58, t-he distal portions of which are turned outwardly at 6) and 62 providing pivots to lbe explained infra. Upwardly extending beyond portions 56 and 55 are guide portions 64 on either side of

wall portions

56 and 58. Overlaying the distal portions 6d and 62 of frame 54 and supported thereby is movable contact assembly 16 which is composed of a flexible contact arm 68 composed of a good electrically conductive material and which possesses good spring characteristics such as beryllium copper. Movable contact arm 68 mounts at opposite ends thereof contacts 7d and 72 attached in a conventional manner and composed of silver or other suitable good electrically conductive material. A stiff actuator plate 74 overlays movable contact arm S. Actuator plate 74 and movable contact arm 68 are both attached in a suitable manner, as by welding, to a support plate 76 which is V-shaped. Actuator plate 74 and -contact arm 63 both conform to this V-shape t-hereby forming a depression in the center of the movable contact assembly 16 which serves as a seat for an actuator roll 116. The contact assembly 16 is pivotably mounted between the two contacts closed positions shown in FIG. 3 and is retained in place on the frame by guide portions 64,

Yoke member 88 having a base portion 120 comprises an annular ring 122 to which is attached an axially extending flange and bifurcations 77 and 75. A pin 94 is supported between the distal portions of

bifurcations

77 and 78. Pin 94 pivotably mounts a toggle arm 92 which is inserted and movable in a slot S3 provided in yoke 88.

Y t means.

-f other end 132 of bellows 130 is hermetically sealed as by soldering about the periphery of togglev arm 92 ,beyond an axially extending flange 124 on arm 92 which flange serves Vas a seat for Ibellows end 132. see particularly FIG. 3, that the pivot 94 of toggle arm 92 is conveniently located within the convolutions of the bellows so that the amount of ilexure each convolution is .subjected to is minimized upon movement of arm 92.4

Bushing 86, externally threaded to facilitate mounting of theswitch 10,`is formed with a ange 85 on its lower end and inserted through a mating aperture in Cover member 82 and is suitably fixed yto said cover as by welding at. 'Y 87 around the periphery of flange 85.` Bushing 86 along with cover 82 is placed over yoke 8S Aand bellows 130 Vand is attached thereto by suitable means as by resistance Welding ilange 90 of yoke 88 to ange 85 of'bushing 86.

`It willbe noted that bushing 86 is recessed at 128 to receive bellows 130. A flexible gasket 98 of conventional material, such Ias rubber, is placed in the top of bushing 86 around toggle arm. 92 to exclude romthe bellows area gross contaminants such as dirt, grit and so on.

Annular portion 91 of yoke 8SY serves as a stop for portion 93;'V of toggle arm 92 thereby limiting the pivotal movement of arm 92, One end of toggle arm 92 is prefer-ably provided with cap 95 and the other end 96 is inserted in aperture 102 in a toggle block 104. Toggle block 104 houses actuator roll 116 and its mounting Block 104 is provided with a slot 106, shown best in FIG. 1, in which is slidably received web 44 of casing 14 which acts as a guide member for block 104. VBlock 104 is provided with two portions107, one for each pole, Yin each of which is formed an aperture 108 which mounts actuator member 110 which is slidably received i thereilrg As may ybest be seen in FIG. 2, actuator mem- Vber 110 is provided with a cavity 111 which acts as a ns eatfor actuator spring 112 which isplaced between actuator member 110 and the bottom of cavi-ty 108 in toggle v'blockr104- Actuator member 110 is provided Vwith bifurcations 115 which mount pin 114 which in turn mounts vactuator roll V116 which can be composed of a self-lubricating material such as an oil impregnated material. Actuator roll 116 serves to transmit force from the toggle arm 92` to the movable contact arm assembly 16 with aV minimum amount of friction loss. Spring 112 biases actuator member 110 Vand roll 116 downwardly against `actuator plate 74, Contact armr68 and frame 54. Cover 82 mounting toggle arm 92 ishermetically attached to container 1S, as by Vwelding at 81. The cover is hermeti- Vcally. attached to ange S formed on the upper wall of container 18 to completely hermetically seal the enclosed toggle switch. f FIG. 1 shows the contacts'in an at-rest open position f with actuator roll 116 located in the Vshaped depression formed in movable contact assembly 16. When the toggle arm 92 is moved in direction a to the solid line position shown in'FIG, 3, roll 116 passes beyond distal pivot portion 62 beyond which point the roll 116 and actuator member 110 moves out of cavity 108 and biases, by means of spring 112, I'actuator plate 74 and movable contact arm 68 in a contact closing direction where-by contact 70 engages contact button 21.

FIG. 3 shows in phantom lines an alternative position for toggle arm 92 moved in direction b whereby contacts 72 and 23v areengaged which is identical but reversed

tothe contacts

70, 21 closed position.

The switch may be connected to existing circuits by any conventional means such as the terminal lockwashers and screws 8 illustrated.

It will be noted,y

As seen in FIG. 3, solid line position, current may be traced from a common middle terminal 24, through frame 54, contact arm 68, contact 70, contact button 21 to terminal 20. In the phantom line position, current ows from the common terminal 24, through frame 54, contact arm 68, contact 72, contact button 23 to terminal 22. It will be seen that in the position shown in FIG. l with the toggle in the center position, both circuits are open.

It may thus be seen that the instant construction provides a true hermetic seal for a toggle type switch as well as providing a true hermetic sealed construction for a terminal assembly.

In view of the above, it will be seen that these several objects of the invention are achieved and other advantageous results obtained.

It is to be understood that the invention is notlirnited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As many changes could be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in accompanying drawings shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

I claim:

1. A hermetically sealed toggle switch having a base yand mounted therein terminals and a movable contact assembly which is actuated by a toggle arm comprising,

(a) an open-ended cup-shaped container for said switch,

(b) a cover having an aperture therein covering the open end and hermetically xed` to said container',

(c) yoke means having a base with a slot therein and two bifurcations,

(d) a pin supported between the distal portionskot said bifurcations,

(e) a togglef arm pivotably mounted on said pin and adapted to pivot within -said slot,

(f) an outwardly extending ange on the base of said yoke means,

(g) a bushing having an outwardly extending flange on one end,

(h) metal bellows having two open ends, one en d thereof hermetically attached to said toggle arm, the other end thereof hermetically attached to said base of said yoke means, the pivot being located within said bellows,

(i) said yoke means and bellows telescopically received within said bushing,

(j) said flange on said yoke means hermetically attached to said flange on said bushing and said ange on said bushing hermetically attached to said cover, and

(k) gasket means placed between said toggle arm and said bushing. Y

2. Seal means lfor a pivotal arm comprising,r

(a) a yoke having a base and pivotably supporting,

(b) a pivotal arm,

(c) a bellows having two ends, one end thereof hermetically attached to said pivotal arm, the other end thereof hermetically attached to said base of said yoke, the pivot of said pivotal arm located within said bellows, and

(d) means protectively enclosing said bellows.

3. An electric switch having a plurality of terminals comprising,

(a) a container having a bottom wall formed with an aperture for each terminal,

(b) a base of electrical insulating material formed with an aperture for each terminal which mates respectively with the apertures in said container,

(c) for each terminal a cylindrical element having a co-axial bore and constructed of electrical insulation material metallized on one face thereof and on the inside periphery of the bore throughout its entire length and on the outside peripheral surface throughout a portion of its length, said elements inserted into the respective mating apertures in the container and base so that said container engages said outside peripheral metallized portion,

(d) said container soldered to each outside peripheral metallized portion,

(e) an electrically conductive contact member provided with an outwardly extending tlange on one end thereof, telescopically inserted in the -bore of each said cylindrical element so that said flange engages said metallized face, said contact member soldered to the metallized layers,

(f) electrical insulation barrier means on said base isolating each terminal,

(g) electrical insulation potting compound placed between said barrier means and said container and between said cylindrical elements and said barrier means thereby forming a protective enclosure for said terminals, and

(h) fastening means to attach electrical leads to said terminals.

4. Sealing means for a terminal structure in an electric switch comprising,

(a) a metal mounting wall having a anged aperture therein,

(b) an electrically insulating contact support element provided with a bore therein,

(c) a metallized layer extending around the periphery of said contact support element throughout a portion of its length and on a face of said contact support element,

(d) said contact support element located within said aperture and aligned so that the flange in said aperture contacts said metallized layer and is hermetically xed thereto,

(e) an electrically conductive contact member provided with an outwardly extending flange on one end thereof telescopically received in said bore and extending from an entrance side through an exit side of said contact support element so that said flange engages the metallized layer on the said face of said contact support element circumscribing said entrance side,

(f) said conductive contact member hermetically fixed to said metallized layer,

(g) fastening means to attach electrical leads to said 4contact member,

(h) electrical insulation barrier means isolating said terminal, and

(i) electrical insulating potting compound placed around said element.

5. A hermetically sealed switch comprising the terminal assembly according to claim 3 and further comprising,

(i) a toggle member for actuating said switch,

(j) a yoke having a base and pivotably supporting said toggle member, and

(k) a tapered bellows having two ends, one end thereof attached to said pivotably mounted toggle member, the other end thereof attached to said base of said yoke, the pivot of said toggle member being located within said bellows.

6. A switch according to claim 5 further including,

(l) means enclosing and protecting said bellows.

References Cited by the Examiner UNITED STATES PATENTS 3,248,511 5/1966 Heilman 20G-168 ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner.

Claims

2. SEAL MEANS FOR A PIVOTAL ARM COMPRISING, (A) A YOKE HAVING A BASE AND PIVOTABLY SUPPORTING, (B) A PIVOTAL ARM, (C) A BELLOWS HAVING TWO ENDS, ONE END THEREOF HERMETICALLY ATTACHED TO SAID PIVOTAL ARM, THE OTHER END THEREOF HERMETICALLY ATTACHED TO SAID BASE OF SAID YOKE, THE PIVOT OF SAID PIVOTAL ARM LOCATED WITHIN SAID BELLOWS, AND (D) MEANS PROTECTIVELY ENCLOSING SAID BELLOWS.