US2831944A

US2831944A - Electric switch

Info

Publication number: US2831944A
Application number: US536481A
Authority: US
Inventors: Miller Stephan
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1955-09-26
Filing date: 1955-09-26
Publication date: 1958-04-22
Anticipated expiration: 1975-04-22

Description

April 22, 1958 s. MILLER 2,831,944

ELECTRIC-SWITCH Filed Sept. 26, 1955 3 Sheets-Sheet 1 WITNESSE Fig IQ L [I2 INVENTOR M1 4 Stephan M i l ler. WWA M ATTORNEY 'April 22, 1958 s. MILLER 2,831,944

ELECTRIC SWITCH Filed Sept. 26, 1955 3 Sheets-Sheet 2 5 Sheets-Sheet 3 Filed Sept. 26, 1955 United States Patent ELECTRIC ITCH .Stephan Miller, Beaver, Pa., ,assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., :1 corporation of Pennsylvania Application September 26,1955, Serial No. 536,481

8 Claims. (Cl. 200-114) :be simple and efficient inoperation and which may be economically manufactured and installed.

A more specific object of my invention is to reduce the size and simplify the structure of the components ofan electric switch without impairing the performance ofthe switch.

Another object of my invention is to provide a onepiece contact and terminalzmember for a switch of :the knife-blade type, thus keeping the number of joints in the electrical circuit toa minimum.

A further object of my invention is to providea combined hinge and fuse contactmember for the "switch.

Still another object of my invention is :to provide a spring clip fora fuseholder which is removablyattached to the fuse contact member. a g

A still further objectso'f my .invention is to provide a base unit which may :be {utilized to amount {either the .break contact assembly, the;hinge contactassemblyor the fuse contact assembly ofithe. switch.

Another objectof my inventiontiszto provide a :neutral assembly which may be:mountedtunderneathgonetrofzthe .fuses .for the switeh-or-ononeofithe base units tin-place of. one pole of the: switch. I

A further-objecttof rnyinvention is to'rnaintain pressure on the switch blades at .the hinge contact of the switch.

Other objects ofmy'invention wilhbeexplained fully hereinafter or ,will be apparent to thoseskilled in the .art. in accordancewith one embodimentofvmy invention,

t the contact-members of an enclosed switch. are mounted on spaced insulating base units whichare attached to the bottom ofthe enclosingbox. The;hinge.contact for each ,pole is of .a .U vshapein .one .piece with a switch blade-hinged on one leg and a fuseholder-on thc'other .leg of. the. U. The break contact and thelowerfuseacontact are eachofan angle shape witha terminallugon one Fig. 3 is :an enlarged view, in side elevation, of the structure shown in Fig. 2;

Fig. 4 is an enlarged view, in end elevation, of the structure showniin Fig. 2; I

Figs. 5 and 6 'are'enlarged views,in elevation and plan, respectively, of a; fuse clip provided for the switch;

Fig. 7 isan.enlarged'detailview of one of the break contacts of the switch;

Figs. 8 and;9 are -vie'ws,in;plan and elevation, respec- -tively, of a hinge and fuse contact ofthe switch; and

Fig. .10 isaview, in .plan,-1of-a different neutral assem bly from that shown in Fig. l.

Referringto the drawings, and particularly to Fig. l, the :enclosed switch shown :therein comprises a sheet metal housing 1.0 having ;a hinged cover .11, a plurality :of insulatingbaseslZ attached to the rear or bottom wall .of the. housing 10,.blade assemblies 13, an operating bail or crank 14 journaledin the side walls of the housing .10,:fuses 15, and a neutralassembly 16. The housing 10 may be of the usualbox-like construction. Itisprovidedwith the usual

knockout portions

17 and 18. It is also provided 'with keyhole openings 19 for mounting .the'housing on a :wall or other support.

xThepresent switch is of the three-pole type. Since the switch membersfor each pole are of the same construction, the members .for only one pole will 'be described in detail. I

Heretofore, it has been the practice to provide switches when fuses ;are not required. In the present structure,

threefbase units 12 are provided. These baseunits are similar in structure andinterchangeable inthe switch.

*When fuses are not required, only two base units are supplied. Since the base units are interchangeable, a

log, the other legheing.acontactmember. Each fuseholder comprises aspring clip whichisheldonthe contact member .by friction and has :a projecting tongue which functionsasastop for the fuse blade. .A neutral assembly may. bemounted underneaththe middlefusein athree-pole switch or on the lowerbasein lieu'of one of .the fuses ina two-pole switch.

Fora better understanding ofzthenatureand objects 7 blies utilized in the switch, the enclosing box .being omitted;

quantity ofunitsof only one design is manufactured. I

The base units'are-preferably moldedfrom a suitable insulating material.

As shown most clearly in Figs. ,2 and 3 each blade assembly 13 comprises twoblades 21, which are preferably composed of hard spring copper or other suitable material, two insulating hookmembers 22 and two leaf springs 23, all of which are held together by two rivets 24. As shown in Fig. 2, the blades 21 are joined together at their center portions and areflared outwardly at both ends to straddle hinge and 'break contact members. The hook members 22 are disposed on the outer sides of the blades '21,an'd the leafsprings23 are disposed on the outer-sides of the hook members 22. The springs 23 function to increase the contact pressure of the blades on thebreak contact member. As shown'in Fig. 7, the ends oftheblades 21, which engage the break contact member, arecurved to facilitate the engagement of the blades with the contact member.

As also shown in Fig.7, the breakcontact member is of an angle'shapehaving a leg 25 disposed parallel'to the base 12 and a leg 26 disposed perpendicular to the base 12. Theleg25 is attached to the base 12'by a screw 27. The leg '26 is engaged by the switch blades 21 when the blades arein" the closed position. A'terminal'lug- 28 is also attached to the leg 25 by a screw 29. Thus, a one-piecernemberfunctions as a break contact member and a terminal member for connectinga line conductor to'the switch.

As-showd-inFig. 2, the blades 21 arehinged on a hinge contact-member which is of a U-shape. -As shown in Figs. 8 and 9,the hinge contact member has two legs Blend 32. Thenblades21 are hinged on the leg'31, and

the leg 32 is provided with a fuseholder '30, as will be described more fully hereinafter. The hinge contact member is attached to a base 12 by a screw 27 which is threaded into an opening 33 provided in the bight of the U. As shown in Fig. 2, a bolt 34 extends through the switch blades 21 and the leg 31 of the U-shaped hinge contact member. A spring washer 35 is provide between the head of the bolt and one blade 21. A nut 36, which is of a spring type, is disposed on the bolt and engages the other switch blade. Thus, the spring washer 35 and the spring nut 36 cooperate in maintaining contact pressure of the switch blades on the hinge contact member. As shown, the fuseholder 30 is disposed on the side of the leg 32 opposite the end of the bolt 34. Thus, a simple one-piece member functions as the hinge contact and cooperates with a spring member to constitute an upper fuse contact for the switch.

As shown most clearly in Fig. 4, the lower fuse contact for each pole of the switch comprises an angleshaped member of copper or other good conducting material and having a leg 37 disposed parallel to the base 12 and a leg 38 disposed perpendicular to the base 12. The leg 37 is attached to the base 12 by a screw 27. A terminal lug 28 is attached to the leg 37 by a screw 29. A fuseholder 34 is attached to the leg 38 for engaging a blade 39 of a fuse 15.

Heretofore, fuseholders for use with fuses of the knife-blade type have been of two general types, namely, a spring pressure type and a clamp type. The fuseholders of the spring pressure type are usually made from hard drawn copper or a copper alloy having a spring characteristic to provide contact pressure. One disadvantage of this type is that operating temperatures may anneal the jaws of the fuseholder and impair the spring characteristic of the jaws. In order to overcome this, additional reenforcing springs of various types have been provided to supplement the spring pressure of the jaws of the fuseholder. The additional springs increase the cost of the fuseholder and require additional space,'thereby increasing the size of the complete switch unit. The fuse holders of the clamp type in which the contact pressure is obtained by tightening a clamping bolt or screw have a disadvantage of becoming loose because of expansion and contraction caused by heating of the contact parts.

In order to overcome the foregoing disadvantages, I have provided the fuseholder 30 which, as shown in Figs. 4, and 6, comprises a spring clip 41 of steel or other spring material and having oppositely disposed ears 42 which extend around the edges of the leg 38 of the fuse contact member. The clip 41 is provided with an integrally formed tongue 43 which remains between the leg 38 and the clip 41 when the clip 41 is sprung away from the leg 38 by the insertion of the fuse blade 39. Thus, the tongue 43 functions as a stop for the blade 39. The spring clip 41 may be slipped over the leg 38 of the contact member and is retained in place by the initial deflection of the spring clip. When the fuse contact blade 39 is inserted the spring load is increased, thereby providing the necessary contact pres sure between the blade 39 and the leg 38 of the contact I member.

It will be noted that the upper end of the spring clip 41 is bent outwardly, thereby reducing the contact area between the spring clip 41 and the fuse blade 39. Since the entire surface of one side of the fuse blade 39 is in contact with the copper contact member 38, most of the current flows through this contact area and not through the spring clip 41 which has higher resistance. Therefore, heating of the spring clip is avoided, and the clip does not lose its spring characteristic. As previously explained, a fuseholder 30 is also utilized on the one leg 32 of the hinge contact member.

As shown in Figs. 1, 2 and 3, the neutral assembly 16 is mounted underneath one of the fuses 15. The neutral assembly 16 comprises an insulating base 45 which is attached to the bottom of the housing 10 by screws 46 and a neutral plate 47 which is attached to 4 the base 45 by a screw 48. A bonding or grounding screw 49 may be inserted through the plate 47 into the housing 10, if desired. Terminal lugs 28 are provided on the neutral plate 47 and a curved lug 51 is also provided for making terminal connections to the neutral plate. Since the neutral assembly is located underneath one of the fuses in the three-pole switch construction, no additional space is required for the neutral assembly.

When only a two-pole switch is provided, the neutral assembly 16 may be mounted on the lower base 12 in place of the contact members forthe one pole of the switch. This arrangement is shown in Fig. 10 of the present drawings. The base 12 is so constructed that the neutral plate 47 may be attached to the base 12 in the same manner as it is attached to the base 45. Connections may be made to the neutral plate in the manner previously described.

From the foregoing description, it is apparent that I have provided an enclosed switch whichis of a simple construction and comprises relatively few parts which are so constructed and mounted in the switch that they require a relatively small amount of space. Since the parts are simple in structure, they may be manufactured and assembled at a relatively low cost. Thus, I have provided a switch which may be manufactured and sold at a relatively low cost without impairing the operating efiiciency of the switch.

Since numerous changes may be made in the abovedescribed construction and different embodiments of the invention may be made'without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a multi-pole switch, in combination, a plurality of spaced elongated insulating base units, each pole of the switch comprising a generally U-shaped hinge contact mounted on a first one of said bases, a switch blade hinged on one leg of the U, a fuseholder on the other leg of the U, the entire fuseholder being above the base of the U, an angle-shaped break contact mounted on a second one of said bases, one leg of said angle being parallel to the base and the other leg perpendicular to the base, the perpendicular leg of the angle engaged by the blade, a terminal member attached to the parallel leg of the angle, a second angle-shaped contact mounted on a third one of said bases, a second fuseholder on the perpendicular leg of the second angle-shaped contact, a second terminal member attached to the parallel leg of the second angle-shaped contact, a one-piece crank disposed substantially parallel to the longitudinal axes of the base units for actuating all of the switch blades about their hinge points, and said base units being similar in structure and interchangeable in the switch.

2. In an enclosed multi-pole switch, in combination, a box-like housing, three spaced elongated insulating base units attached to a rear wall of the housing, each pole of the switch comprising a generally U-shaped hinge contact mounted on a first one of said bases, a switch blade hinged on one leg of the U, a fuseholder frietionally held on the other leg of the U, the entire fuseholder being above the base of the U, an angle-shaped break contact mounted on a second one of said bases, one leg of said angle being parallel to the base and the other leg being perpendicular to the base, the perpendicular leg of the angle being engaged by the blade, a terminal member attached to the parallel leg of the angle, a second angleshaped contact mounted on a third one of said bases, a second fuseholder frietionally held on the perpendicular leg of the second angle-shaped contact, a second terminal member attached to the parallel leg of the second angleshaped contact, a one-piece crank rotatably mounted in opposite side walls of the housing and extending substantially parallel to the longitudinal axes of the base i to said rear Wall of the housing.

prising a generally U-shaped hinge contact mounted on a first one of said bases, a switch blade hinged, on one leg of the U, a fuseholder on the other leg of the U, the entire fuseholder being above the base of the U, an angleshaped'break contact mounted on a second one of said bases, one leg of said angle being parallel to the base and the otherleg being perpendicular to the base, the perpendicular leg of the angle being engaged by the blade, a terminal member attached to the parallel leg of the angle, a second angle-shaped contact mounted on a third one of said bases, a second fuseholder on the perpendicular leg of the second angle-shaped contact, a second terminal member attached to the parallel leg of the second angle-shaped contact, a one-piece crank disposed substantially parallel to the longitudinal axes of the base units for actuating all of the switch blades about their hinge points, a neutral plate, and an insulating base disposed between said first base unit and said third base unit for supporting the neutral plate. a

4. In an enclosed multi-pole switch, in combination, a box-like housing, three spaced elongated insulating base units attached to a rear wall of the housing, each pole of the switch comprising a generally U-shaped hinge contact mounted on a first one of said bases, a switch blade hinged on one legof the U, a fuseholder on the other leg of the U, the entire fuseholder being above the base of the U, an angle-shaped break contact mounted on a second one of said bases, one leg of said angle being parallel to the base and the other leg being perpendicular to the base, the perpendicular leg of the angle being engaged by the blade, a terminal member attached to the parallel leg of the angle, a second angle-shaped contact mounted on a third one of said bases, a second fuseholder on the perpendicular leg of the second angle-shaped contact, a second terminal member attached to the parallel leg of the second angleshaped contact, a one-piece crank rotatably mounted in opposite side walls of the housing and extending substantially parallel to the longitudinal axes of the base units for actuating all of the switch blades about their hinge points, and a neutral plate, said plate-being mountable on oneof said base units in place of one of the fuse contacts;

5. In aswitch, in combination, a plurality of spaced insulating base units, a generally U-shaped hinge contact mounted on a first one of said bases, a switch blade hinged on one leg of the U, a fuseholder on the other leg of the U, means for actuating the switch blade about its hinge point, an angle-shaped break contact mounted on a second one of said bases, one leg of said angle being parallel to thebase and the other leg being perpendicular to the base, the perpendicular leg of the angle being engaged by the blade, a terminal member attached to the parallel leg of the angle, a secondangle-shaped contact mounted on a third one of said bases, a second fuseholder on the perpendicular leg of the second angle-shaped contact, a second terminal member attached to the parallel leg of the second angle-shaped contact, each one of said fuseholders comprising a spring clip having oppositely disposed ears thereon slidably engaging the leg of the contact, the clip being held on the contact by spring pressure developed by defiection of the clip, and a tongue on the clip disposed between the clip and the leg of the contact to function as a stop for a blade of a fuse.

6. In an enclosed switch, in combination, a housing,

a plurality of spaced insulating base units attached to one wall of the housing, a generally U-shaped hinge contact mounted on a first one of said bases, a switch blade hinged on one leg of the U, a fuseholder on the other leg of the U, crank means for actuating the switch blade about its hinge point, an angle-shaped break contact mounted on a second one of said bases, one leg of said angle being parallel to the base and the other leg being perpendicular to the base, the perpendicular leg of the angle being engaged by the blade, a terminalv member attached to the parallel leg of the angle, a second angle-shaped contact mounted on a third one of said bases, a second fuseholder on the perpendicular leg of the second angle-shaped contact, a second terminal member attached to the parallel leg of the second angleshaped contact, each one of said fuseholders comprising a spring clip having oppositely disposed ears extending partly around the leg of the contact to slidably engage the contact, the clip being held on the contact by spring pressure developed by deflection of the clip, and an integrally formed tongue on the clip disposed between the clip and the leg of the contact to function as a stop for a blade of a fuse.

7. In an electric switch, in combination, an insulating base, a generally U-shaped contact member having the bight of the U attached to the base, a switch member hinged to one leg of the contact member, aspring clip having oppositely disposed ears bent around the other leg of the contact member to slidably engage the contact member, the clip being held on the contact member by spring pressure developed by deflection of the clip, and an integrally formed tongue on the clip disposed between the clip and the contact member to function as a stop for a blade of a fuse.

8. In an electric device, in combination, an insulating base, a contact member having a leg disposed perpendicular'to the base, a spring clip having oppositely disposed ears extending partly around said leg to slidably engage the contact member, the clip being held on the leg by spring pressure developed by deflection of the clip, and a tongue formed integrally with the clip, said tongue being in engagement with said leg when a fuse blade is inserted between the leg and the clip.

Daly Oct. 17, 1950