US2724028A - Electric switching apparatus - Google Patents

Description

Nov. 15, 1955 R. G. PAGE EIAL 2,724,028

ELECTRIC SWITCHING APPARATUS Filed July 20, 1953 2 Sheets-Sheet 1 Ilml IIIIIIIIIII:

Invent/cars Robert 6. Pa e Robert $.Tillson Their Attorney Nov. 15, 1955 R. cs. PAGE ETAL 2,724,028

ELECTRIC SWITCHING APPARATUS Filed July 20, 1955 2 Sheets-Sheet 2 Inventors Robert G. Page Rob ebb STE Ison Their Attorney.

United States Patent-O ELECTRIC SWITCHING APPARATUS Robert G. Page, New Britain, and Robert S. Tillson,

Collinsville, Conn., assignors to General Electric Company, a corporation of New York Application July 20, 1953, Serial No. 369,202

7 Claims. (Cl. 200-46) The present invention relates to improved electric switching apparatus and more particularly to an improved snap action operating mechanism especially adapted for use in front operated apparatus of this type.

It is a continual problem for the designer of electric switching apparatus to provide simpler mechanisms and mountings which at the same time retain or improve upon the operating characteristics of the apparatus. The problem is particularly difficult with front operated switches, that is, switches in which the interrupters and operating handle for the mechanism are on the same side of the mechanism.

The present invention has for an important object the provision for simpler and more effective front operated electric switching apparatus.

It is another object of the invention to providean improved snap action operating mechanism.

Further objects and advantages will become apparent as the following description proceeds with reference being had to the accompanying drawing and its scope being pointed out in the appended claims. In the drawing, Fig. 1 is a front elevational view of enclosed electric switching apparatus embodying my invention with the cover partially broken away;

Fig. 2 is a side elcvational view in section taken along the line 2-2 of Fig. l;

.Fig. 3 is an enlarged sectional view of a portion of the mechanism of Fig. 2 showing the operating handle and its connection to the mechanism;

Fig. 4 is a rear view showing the mechanism of Fig. I removed from the enclosure and with the parts shown in the closed position of the interrupters;

Fig. 5 is a similar view to that of Fig. 4 but with the parts shown in the positions occupied in the open circuit position of. the interrupters; and

Fig. 6 is an enlarged exploded view in perspective of the operating handle and mechanism.

Referring now to Fig. l of the drawing, the invention is shown embodied in an electric switching apparatus includinga metal enclosing case 1 having athinged cover 2. Theswitching apparatus is mounted in the case 1 by means of a metal plate 3 which also supports the snap acting mechanism. Three circuitinterrupting units 4, 5 and 6 are supported from a molded insulating base 7 which is in turn supported from the metal plate 3 by means of suitable screws 8. The circuit interrupting units (see Figs. 1 and 2) are each of identical construction and each includes a pair of spaced stationary contact members 9 and 10 which extend between a pair of insulating side plates 11. At the opposite end of the unit is a terminal member 12 extending between theside plates and provided at one end with a terminal portion 12' which may be connected with a similar terminal portion 13 formed on the stationary contact 10 by means of a fuse or, if desired, by means of a conducting strap 14 as illustrated. Thecontact members 9 and 10 and the terminal member 12 are all provided with portions exmember 34.

2,724,028 Patented Nov. 15, 1955 tending through the insulating side plates which are staked over to secure the plate in assembled relation.

Each interrupting unit is secured to upstanding bosses 15 on the insulating base 7 by suitable bolts 16 which extend respectively through an extension of stationary contact 9 and a flange 17 on the terminal member 12. Terminals 18 for making external circuit connections are also secured to the base 7 and in electrical contact with the terminal 12 and stationary contact 9 by the bolt 16.

The circuit between contacts 9 and 10 is controlled by a movable U-shaped bridging contact 19 which is supported for reciprocating movement into and out of circuit closing position. Means for coupling the movable contacts 19 of each interrupter to a common operating rod 20 is provided by the structure 21 which includes lateral extensions 22 received in the longitudinally extending guide slots 23 and U-shaped recess providing opposed drive arms 24and 25 which straddle the operating rod 20. Suitable sleeves 26 of insulating material are provided on the operating rod to insulate the interrupter units from the operating mechanism. The switch units described above are not in themselves my invention and are described and claimed in Rowe Patent 2,494,315, dated January 10, 1950.

From the above description it is apparent that bodily movement of the operating rod 20 in a vertical direction as viewed in Figs. 1 and 2 is effective to move the contacts 19 to open and closed circuit positions. In accordance with my invention, I provide an improved snap .action operating mechanism for effecting this movement.

The rod 20 extends through aligned openings in a pair of arms 27 extending from the edges of a reciprocating plate 28 supported between the metal plate 3 for carrying the operating mechanism and the insulating base 7. The arms 27 extend through suitable vertically extending slots 29 in the insulating base.

In the assembled position of the switch, the operating rod 20 is retained in position by the upstanding flanges 7 molded integrally with the insulating base 7. During assembly, it is possible to move the plate 28 and arms 27 far enough toward the bottom of slots 29 to permit the insertion of the operating rod 20. The snap action mechanismis controlled by an operating shaft 30 which extends through a hub 31 provided on the insulating base 7. The operating shaft is coupled to a rotatably mounted handle 32 provided on the exterior of the cover 2 by means of cooperating pin 33 and U-shaped coupling The operating shaft is provided at its inner end with a flattened portion 35 of rectangular cross section to provide for the driving connection with the operating mechanism. The construction of the operating mechanism is best illustrated in Figs. 3 and 6. As there shown, the operating shaft is retained in the hub 31 by means of a slotted washer 36 which cooperates with a notch 37 in the flattened portion of the operating shaft. The shaft is also journaled in the metal plate 3 by means of a washer-like member 38 which is slotted at 39 to recess the flattened end of the operating shaft. The washer 38 has essentially the same outer diameter as an opening 40 formed in the plate 3 in the center of a flange 41 which is pressed out of plane of the plate 3. Washers 42 and 43 of larger diameter than the washer 38 are also sloted at 44 to receive the end of the operating shaft 30 and these washers engage the opposite sides of theflange 41 to secure the bearing washer 38 in the plane of the flange 41. The assembly carried by the operating shaft also includes a crank arm 45 provided at its one end with the ring-like collar 46 having an inner diameter essentially equal to the outer diameter of the washer 43 so that it may rotate relative thereto and a plate 47 3 which is apertured at 48to receive the end of the shaft. Washers 38, 42, 43 and the plate 47 are secured together by suitable fastening means such as the bolts illustrated at 47. The plate 47 is of larger outer dimensions than the collar 46 so that it retainsthefcrank arm 45 in assembled relation. This plate 47 also provides means for driving the upper end of an arm 49 overcenter with respect to the operating shaft and an apertured support 50 for the lower end of, the arm. (See Figs. 4 and 5,) The support 50 is slotted to permit movement of the arm 49 therethrough and also provides a stop for one end of a compression spring 51 which surrounds the arm 49 and bears at its opposite end on the shoulders 52. Support 50 is,also free to, pivot on the plate 3 so that the openings therein remain in alignment with the arm 49 regardless, of the position of the plate 47 and the upper end of the arm. V a V The actual, driving connection between the operating shaft 30 and the slide 28 is provided by the crank arm 45 and ,a connecting arm 53 pivoted thereto at 54. The connection between the plate 53 and the slide 28 is provided by a pin 55 as best shown in Fig. 3. The pin 55 fits loos'ely in a guide slot 56 formed in the plate 3 to mov'e in a verticaLdirection. An additional guide slot 57 cooperates with a collar 58 formed integrally with the slide 28, U The drive washer 43 is recessed at its outer edge for a substantial angular distance to provide driving shoulders, 59 and 60 and the crank arm 45 is provided with an inward extension for tooth 61 of substantially smaller angular lengththan the recess to provide cooperating drive surfaces 63 and 64. It is believed clear that this construction provides a lost motion driving connection which permits relative movement between the contacts and the operating shaft 30 Movement' of the slide 28 and the contacts is limited by suitable stops in the closed circuit;,position illustrated in Fig. 4. Positioncf the arm 45 and as aresult, position of the movable contactsis limited by the stop 65 provided by the outwardly turned end of the connecting plate 53 which engages the surfaces 66 on the arm 45. Astcp r615 travel in the open, circuit direction is provided by an abutment provided on the plate 3 by the lanced out portion 67 which engages the lower edge of the slide 28.

.. The operation of the illustrated embodiment of my invention will be more apparent from a brief considerationof Fi g s 4, and 6 of the drawing. The parts of "the mechanis rn are shcwn in their closed circuit position 4. As the shaft 30 is rotated in a counterclockwise direction as 'shcw'n in that figure, the plate 47 srarts rn oyerrreht toward the dead center 'posi'tiori "of the toggle formed by that pl'ate'and the arm 49. At about the time that the dead center position is reached, the surface 60 on the driving washer engages the driving surface 64 on the crank arm 45. The toggle then god center and the action of the compression spring serves to qr v lthe a .5 and with we i i l 66h ct f0 I open circuit position with a's'nap action, The p'a'rts then occupy the positions shown in Fig. 5. When the closing eperatiori is effected reason of the operatih'g shaft n a clockw'isedirection as view'ed in Fig', 5, the reverse action takes place with the closing dri'v'e being eif'e'cted by enga gerneht of thedrivingsurface 59 of the washer 43 and the driving surfaces: on the crank arm 45.

the foregoing detailed description it is apparent that our invention provides a very simple switch opeiating rnechanism which may be actuated from the side the panel onwhich the interrupting units are mounted and which insures movement of the Contact into and out of engagement with a snap action. The mechanism is characterized by a minimum of parts for enacting this pe. of per i n. 1 J

While there hasbee ri' shown'and described a particular embodiment of the invention, it will be obvious to those artthat changes and modifications be made without departing from the "invention, and that 4 it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. Electric switching apparatus comprising an insulating base, a plurality of circuit interrupting units mounted on one side of said base and each including a movable contact, a metal plate secured on the opposite side of said base, a snap action mechanism supported 'on theside of said plate away from said base, an operating member supported between said base and said plate for reciproeating movement, means on said operating member and said plate cooperatingto guide said member for movement in a plane parallel to said plate, means coupling said operating member to said snap acting mechanism through said plate and means coupling said operating member to said movable contacts through said base;

2. Electric switching apparatus comprising an insulati'ng base, a plurality of circuit interrupting units mounted on one side of said base and each including a movable contact, a metal plate secured on the opposite side of said base, a snap action mechanism supported on said plate, an operating member supported between said base and said plate for reciprocating movement, means coupling said operating member to said snap acting mechanism and means coupling said operating member through said base to said movable contacts.

3. Electric switching apparatus comprising an insulating base, a plurality of circuit interrupting units mounted on one side of said base and each including a movable contact supported for reciprocating movement, a metal plate secured on the opposite side of said base, a snap action mechanism supported on the side of said plate away from said base, an operating member supported between said base and said plate for reciprocating movement, means coupling said operating member to said snap acting mechanism, means coupling said operating member to said movable contacts through said base, and an operating shaft extending through said base and said plate to provide for operation of said mechanism from said one 'side of said base. a

4. A snap action operating mechanism for the movable contact of switching apparatus comprising a supporthaw ing an opening therethrough, an operating shaft journaled in said opening, a drive washer connected to said shaft for rotation therewith, an overcenter snap acting macs anism including a member coupled to said shaft for rotation therewith, a crank arm rotatably mounted on said driving washer and having a lost motion connection therewith, a contact operating member and a member pivoted on said crank arm and connected to said contact operating member to convert rotary motion of said crank arm to reciprocating motion of said contact operating member.

5. A snap 'actioh operating mechanism for. the movable contact of switching apparatus comprising a metal supporting plate having an opening therethrough, an

7 operating shaft journaled in said opening, a drive washer driving shoulders, 'a snap acting mechanism coupled to said shaft for activation thereby, a crank arm having a flat collar rotatably mounted on said driving washer and supported in coplanar relation with respect thereto, .and a projection carried by said crank arm lying in said recess and having an angular extent substantially less than said recess to provide a' lost motion connection between said driving washer and said crank arm, and means coubring said crank arrn tc a'm'evableeomact. U

'6. A snap action operating mechanism for thc'movable contact for switching apparatus comprising a str s ser having an opening thereth'rough, an operating shaft joiirin said opening, 'a drive washer connect" to said Shaft for rotation therewith and having a 'circumferehtie! recess providing angularly spaced driving shoulders, an overcenter snap acting mechanism including a member coupled to said shaft for rotation therewith, a crank arm,

rotatably mounted on said driving washer, a projection carried by said crank arm lying in said recess and having an angular extent substantially less than said recess to provide a lost motion connection between said driving washer and said crank arm, and means coupling said crank arm to a movable contact.

7. A snap action operating mechanism for the movable contact of switching apparatus comprising a metal supporting plate having an opening therethrough, an operating shaft journaled in said opening, a drive Washer connected to said shaft for rotation therewith and having a circumferential recess providing angularly spaced driving shoulders, an overcenter snap acting mechanism including a member coupled to said shaft for rotation References Cited in the file of this patent UNITED STATES PATENTS 1,785,192 Hammerly Dec. 16, 1930 2,494,314 Rowe Jan. 10, 1950 2,574,290 Rowe Nov. 6, 1951

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