US2010677A - Multi-break electric switch - Google Patents

Description

Aug. '6, ,1935. e. w. OKEEFFE 2,010,677

MULTIBREAK ELECTRIC SWITCH I Filed Jan. 24, 1929 6 Sheets-Sheet l 8- 1935- C .e. w. OQKEEFFE 2,010,677

MULTIBREAK ELECTRIC SWITCH Filed Jan. 24, .1929 v s Sheets-Sheet 2 .Zhvenian Aug. 6, 1935. 5. w OKEEFFE 2,010,677

MUL'IIBREAK ELECTRIC SWITCH Filed Jan. '24, 1929 6 Sheets-Sheet 3 frzve ifivr,

1935- G. w. OKEEFFE MULTIBREAK ELECTRIC SWITCH 6 Sheets-Sheet 4 Filed Jan. 24, 1929 w 2 W r W H, a H %/M 10 5 ar hm 8 M. 7 mm W U 8 Aug. 6, 1935. a. w. OKEEFFE MULTIBREAK ELECTRIC SWITCH Filed Jan. 24, 1929 6 Sheets-Sheet 6 v Patented Aug. 6, 1935 George W. OKeefle,

Condit Electrical Man Milton, at

achwcononfl n.

South Boston, Mann, a corporation of Massachuaetts Application January 24, 1929, Serial No. 334,788

16 Claims. (Cl. 200-16) This invention relates to electric switches which are especially adapted to control the circuits of multi-phase motors up to say fliteen horse power at around six hundredvolts, although not limited to such use.

In a copending application of Chester D. Ainsworth, Serial No. 322,730, filed November 30, 1928, assigned to the assignee of this application, there is disclosed and claimed a switch that is characterized by having four serially-connected points of circuit interruption in each phase'conductor and so arranged and constructed as to eliminate the circuit interrupting arcs that heretoi'ore have invariably been formed when th switch has opened under load.

It is an object of the present invention to provide a switch embodying the principles of the switch of said application.

A further object of the invention is to provide go a'multi-break switch wherein the stationary and movable contact members are carried by horizontal relatively movable supporting plates and operating mechanism to move the movable plate between switch open and switch closed position as while maintaining it in a horizontal position.

Another object of the invention is to provide a switch wherein the movable contact members are supported on a supporting plate carried removably in a movable irame. a

A further object is the provision of means for locking the removable supporting plate for the movable contact members sothat it cannot be removed from operative position when the switch is closed.

Another object of the invention is the provision of a switch which is so designed that the separate parts thereof can be removed either with the fingers alone or by. the use of such simple tools as a screw driver or pliers, so that they can do be inspected, adjusted and repaired readily and also so that the various parts 01' theswitch can be assembled rapidly by inexperienced labor.

In a switch adapted for motor control service,

it has been found that a workman, in connecting 4s the'switch with its circuits, will position the conductors improperly in the enclosing casing, so

that they are liable to foul the operating mechanism and prevent the proper operation 01 the switch.

It is a further object of the present invention to provide guard members which are so positioned within the enclosing casing as to obstruct such passages therein that are not adapted to have conductors extended therethrough.

A further object of the invention is an arrangement orstationary and movablecontact memhere such that the movable contact members are free from flexible leads or other conductors. To this end, an odd number, as three, insulated, stationary contact members and an even number, 5 as two, insulated movable contact members are provided for, each power circuit through the switch. Thus the end stationary contact members can be connected respectively with the incoming and outgoing circuit leads and the movl0 able contact members can be free from direct connection with any leads. I

A further object oi the invention is generally to improve the construction and operation of electric switches.

Pig. 1 is a side elevation of an electric switch' embodying the present invention, the enclosing casing being shown in section.

Fig. 2 is a front elevation of the switch oi Fig.

1, the cover of the enclosingicasing being broken out. F13. 31in a sectional elevation'taken along line Hot Fig. 2.

Fig. 4 is a side elevation of the switch of Fig. 2 with the casing and the relay base removed to illustrate more particularly the arrangement of the closing electromagnet and theoperating mechanism.

Fig. 5 is a plan view 01' the switch.

Fig. 6 is a section taken along line M of Fig.

4 with the movable contact carrier in a partially withdrawn position.

Fig. 7 is a section taken along line |--l of Fig. 6.

Fig. 8 is an enlarged sectional detail taken along line 0-4 of Fig. 5.

Fig. 9 is a sectional detail taken along line 9-9 of Fig. 5.

Fig. 16 is a side elevation of the holding magnet core.

Fig. 11 is an end view of the carrier of Fig. 10.

Fig. 12 is a side elevation of the armature and its holding frame.

Fig. 18 is a plan view of the armature and frame taken along line I3-i3 of Fig. 12.

Fig. 14 is a plan view of the pan that is disposed beneath the armature.

Fig. 16 is a perspective view of the pan of Fi 14.

Fig. 16 is a perspective view of the supporting 50 bracket for the switch.

Fig 17 is a perspective view of plates of the switch frame.

Fig. 18 is a perspective view of the movable holding frame for the movable contact carrier. 55

one of the side Fig. 19 is a perspective detail taken partly in section through one of the side plates to illustrate the construction of one of the operating mecha-'- nisms and its relation with a side plate.

The switch here shown is contained within the enclosing casing having the fixed back part Iii and the front part 22 which is hinged to and constitutesa cover for the back part. The two parts of the casing are latched in closed relation and by the latch 24, see Fig. 2. An attaching bracket 26, see especially Fig. 16, is secured, as welded, to the inner face of the rear wall of the part 20 of the casing and has forwardly extended and oppositely reflexed flanges 28 on which the switch is adapted to be secured. Said flanges carry attaching screws 30 that are screw threaded therein and have their inner ends peened over so that they can not be removed readily from the flanges. The bracket also has a forwardly extended plate 32 which is located between said flanges and is adapted to be disposed behind the operating mechanism of the switch. Said flanges 2B are spaced from the back wall of the casing and terminate close to the side walls thereof, as illustrated clearlyin Fig. 5, and cooperate with the casing to provide vertical ducts 36 for the circuit conductors located at the sides of the casing away from the movable parts of the switch. The forwardly extended plates 32 constitute a barrier which obstructs the vertical passage between the back of the switch and the back wall of the casing and thus prevents the circuit conductors from being extended therethrough which, if they were so extended, might foul the operating mechanism and so prevent the proper operation of the switch The switch includes the lei t and right hand side plates 34 and 36 respectively,- see particularly Figs. '2, 4 and 17. Said plates are provided with pairs of inwardly directed reflexed ears 36 upon -which the stationary contact carrier to rests and to which it is secured. rigidly by the screws 42. Said plates 34 and 36 are provided near the bottoms thereof with inwardly reflexed cars 64 which have intermediate portions 44a that areparallel with said plates and have inwardly directed parallel end portions b that lie near but on one side of the material median lines of said plates. The horizontally-extended ill-shaped core 46 of the operating -and holding electro-mag net is located upon the similar faces of said end portions 44b, so as to be in the median lines of said plates and is riveted fixedly to said end portions by the rivets 41'. Said core and said carrier 40 constitute the means which secures said side plates rigidly in spaced relation, no other means being necessary. Said side plates are also formed at the bottom rear edges thereof with outwardly reflexed flanges 48 which are adapted to bear upon the flanges 28 of the supporting bracket 30. Said flanges 48 have vertically elongated slots 50 therein which communicate v at their lower ends with enlarged circular openings 52 through which the heads of the holding screws 30 can be passed so that the bodies of said screws can enter said slots 50. The arrangement is such that by backing off-said screws 30 and by raising the switch and thereupon by pulling it forwardly, the switch can be removed from its connection with said supporting bracket.

The stationary contact carrier 40 consists of a rigid rectangular plate of some suitable insulating material such asbakelite, or some other material capable of being molded into shape. Said carrier is provided on its under face with gated copper bar or plate at the end and on the under faces of which are provided spheroidally shaped bosses or contacts 56 formed by expressing the material of the bar, and thus providing correspondingly shaped recesses 58, in the under face of said bar. Said bar between said recesses is provided with an internally screwthreaded passage 60 in which an attaching bolt 62, which is passed through the insulating plate 80, is removably screw-threaded whereby to secure each contact member separately to said insulating plate.

The stationary contact members of the sets are received in parallel grooves M formed in the underside of said carrier-plate whereby the contact members are held against lateral or rotary movements and thus are maintained permanently in alignment.

The end contact members 5% and MD are adapted to be connected to the conductors of the power circuits. To this end, a terminal plate 66 is received in theends of each of said slots 64 under the contact members 55 and 64b. Said plates have upstanding ears 6B which overlie the front and rear sides of said carrier-plate and are provided with attaching screws 10 for' the circuit leads. to the carrier plate by a screw i2. Each plate is thus secured independently of the securing means for the contact members which consequently can be removed for inspection without Each of the plates 66 is secured disturbing said terminal plates or their connections with the conductors. The intermediate contact members Eduare secured in said slots 64 each by an attaching screw 14. Connectors I6 are also clamped to said carrier plate by said screw and provide terminals to which the control circuits for the operating electro-magnet are connected.v Anupstanding ledge 18' of said car-.- rier plate provides a barrier between the screws 68 and the terminals and also constitutes means to hold said terminals against rotation. The plate is also provided with depending barriers to which are located on opposite sides of and between the sets of stationary contact members and also in front and in the rear of the end contact members of said sets for the purpose of preventing intermingling of the arc gases of the various phases when the switch is opened upon overload or on voltages far in excess of the load and voltage for which the switch is designed. The design of the switch is such that when it is operated on such voltages that the voltage across any point of circuit interruption is less than approximately two hundred volts and where the current is such that the contacts 56 do not become heated to an ionizing temperature during the first half cycle of current flow, the circult is caused to be interrupted completely at the end of the first half cycle of current flow without the formation of the usual arcs. Consequently, when the switch is operated on circuits for which it is designed, these barriers are unnecessary.

The movable contactmembers 84 are carried "three horizontally spaced sets of contact members each set of which consists of two spaced contact members N. All of said contact members are identical and interchangeable and are similar in construction with the stationary contact members 84 andhave similarly formed contactbossesllattheiroppositeendsandarecess l8 between said'bosses. Bald movable contact members are located beneath the stationary contact members and in position each to engage an inner boss of the outer contact members I and Nb and a separate boss of the common inner contact members No, thus to control the circuit between said contact members I4 and 54b and to provide four points of circuit interruption'in series for each phase conductor.

Each movable contact member is supported resiliently and removably by said carrier plate II.

Tothisendseeespeciallyl'lgs.3,dand7,the

carrier is providedunder each contact member with a rectangular depression ll in its upper face in which channel shaped brackets 02 are seated. The legs "a of said'channels-extend above said carrier-plate and ,overlie the opposite sides of said contact members and have their upper ends reflexed inwardly to provide opposed horizontal ears or abutments N against which the upper faces of the movable contact members between the bosses thereof are pressed yieldingly and removably.

The contact members are each supported on the enlarged flange SI of a supporting pin I! which is slidably extended vertically through an opening in the carrier at the bottom of the recessand r has areduced upper end III that is located re- '40,

movably in the aperture II in the contact member and constitutes a fulcrum therefor about which the contact membercan tilt to align itself with the cooperating stationary contact members. A compression spring ll! encircles the pin I8 and bears against the bottom member 02b, channel member .2 and also against the flange N of said pin whereby to hold the contact member yieldingly against the reilexed ears .4 of the channel member, and'also to hold said channel member in its recess in said carrier. The bottom end of said pin is provided with a button i, under said carrier, which is adapted to be grasped-between the fingers and pulled down- I wardly whereby to compress the spring I" and 5:;

to withdraw the pin from its engagement with the contact member, thus permitting the con tact member to be removed from the carrier. The button I also serves to limit the upward movement of the pin when the contact member is removed, thereby to prevent the disengagement of" the parts.

' Barriers II! are extended from front to rear of said carrier II- between said sets of movable contact members but are unnecessary except under conditions that render the barriers ll necessary.

The movable contact members and the supporting structure therefor are described and claimed in my divisional application filed Februcry 20, 1929, Serial No. 341,519, now Patent No. 1,895,767. 1

The carrier .2 is .removably supported in a holding frame that is movable vertically to open and close'the switch. Said holding frame, see especially Fig. 18, consists of a horizontal metal slots I26.

end walls ill and inwardly turned horizontal edges II! which constitute tracks that support the movable carrier I2. Said carrier is provided with parallel guide slots Ill in its opposite end faces in which said tracks III are loosely'received. The forward edge of said carrier is provided with a handle Hi, see especially Pig. 6, by which the carrier, with its contact members, can .be withdrawn from the track and removed entirely from the switch. A leaf spring H8 is fixed at one end to the plate ill and has an upwardly directed projection I20 that is adapted to spring into a notch I22, see Figs. 3 and 7, of the movable carrier whereby to hold the carrier releasably in operative position. The carrier frame has a pair of inwardly-directed projections H3 at the rear thereof which are adapted to be abutted against by the removable contact-supporting carrier 82, whereby to limit the horizontal movement of the carrier and define the operative location thereof.

The horizontal position of the metal plate III is provided with an aperture H6 therein below the buttons I M of the contact-supporting pins 08 so that said buttons can enter said aperture in their depressed switch-closed positions without engaging the carrier frame.

An important feature of this constructionl-by.

which the movable contact carrier 82 can be wit'lidrawn and inserted in an inverted position in thei' holding frame, whereby to provide an effective? lock out for the switch, is described and claimedin my continuing application Serial No. 509,726,

is in switch closed position, whereby to lock the plate against horizontal movement. Whenthe plate is in switch-open position, however, it is free from holding engagement with said ears and so is free to be withdrawn from the switch.

Said carrier frame is guided for vertical movement by and between the side plates 34 and I. Said side plates are provided with pairs of inwardly directed parallel ears I" at both their front and rear edges. see especially Fig. 1'7, which are loosely received in spaced vertical slots I" formed in the upstanding side walls ill of said frame. The frame is thus guidedfor vertical, movement in parallel lines by said ears and also is prevented from undue lateral movement by the engagement of said ears with the bottoms of said Bald frame is reci'procated by operating mechanism that is duplicated at each end of the frame.

- The bottom plate ill of the. frame, at each side,

19, the lower endof which is pivoted to the new sontal leg I32 of a bell crank lever I. Said bell crank lever is pivoted on a pin it. carried by a sideplateatther'earofthevertiealmedianline.

thereof and is spaced therefrom by a spacing member I". The vertically extended leg 14. of

said bell crank lever is pivoted by a pin in to one s end of a toggle link i. The free end'of said link is pivoted to the reduced end Ill of a pin illwhich pin has an enlarged section III that extends loosely through a vertically extended arm cally movable in said slot I50 to guide the end of said link I for vertical movement in a straight line; and the pin is'adapted to bear against said confronting faces in switch closing and opening movements. Each of said arms I52 is received on its pin between said reflexed ears and the link I and operates in the space between said reflexed. ears I55 and the body of the side plate. Said side plate is also provided with a set of inwardly directed struck out parallel ears I50 which are lo- I55 and constitute additional guiding means for the vertical movement of the arms I52. The arrangement of the mechanism is such that the links I are straightened and move almost into hor zontal positions, or normal to said faces I51, when the arms I52 are raisedwhereby to ra se the movable contact members into pressure applying engagement with the cooperating stationary switch members. The links I coo erate with the pins I48 and the vertical slots 58' to form abutment-toggles by which the operating force that actuate the arms I52 is enhanced at the cooperating contact members.

Said arms I52 are connected integrally at the lower ends thereof by a horizontal plate I52, see especially Figs. 4, l2 and 13, on which the barshaped armature I05 for the actuating electromagnet 46 is received. Said armature is provided with opposed sideplates I55 that extend beyond the ends of the armature and overlie the singularly-inclined lower ends I55 of said arms I52 whereby to hold the armature from undue lateral movement on said holding fram Said holding frame is provided with integral struck out with said frame whereby it can align itself with the poles of said magnet core 45 and prevent undue noises when the magnet is energized. Said pins can also be removed readily from the front of the enclosing casing whereby ,to remove said armature from its holding frame upon need. The magnet core 45 is provided with an energizing winding or coil I12 which is adapted to be energized to raise the armature holdingframe and close the switch and to remain energized for so long as the switch is closed.

A guard plate I14 is disposed beneath said armature holding frame and has an upturned front edge Iii-located in front of said armature and extends rearwardly, beyond said armature and is terminated adjacent the rear wall of the fixed part 20 of the enclosing casing. Said plate has'up tanding side arms I10 which overlie the side plates 88 and 35. The upper ends of said arms III are provided with slots I00 therein which are open at the tops and in which attaching screws I82 carried by. said side plates are re- I on opposite sides of said slots I80, which ears are adapted to engage the heads of said screws thus to support the plate against down- 'with the control circuits of the switch.

frame'at will.-

ward movement when the screws are screwed down. Said screws I82 are permanently secured in said side plates by heading overthe inner ends thereof but can be backed out enough to permit theears I84 topass between the heads of said screws andsaid side plates. Said upstanding arms I18 are provided with inwardly-directed upwardly-inclined projections I85 which are adapted to enter slots I88 of said side plates and bear against the inclined faces I90 of said slots whereby to cooperate with said screws I52 in holding said plate removably in position. Said plate is also provided with ,an upstanding proiection I92 which engagesand constitutes a support for the actuating coil I12 of the electro-- magnet. Said plate constitutes'means to shield the armature-carrying frame from contact with the circuit conductors. when said plate is removed, and the armature is removed from its frame, the actuatingcoil I12 can be removed from its core and withdrawn through the space between said core and the armature frame.

A relay panel I95 is located in front of the switch and is attached by screws I96 toinwardly extended ears I98 of the side plates 34 and-05. Said panel is composed of insulating material and has upper terminals I98 which are connected by bare strap conductors 200 to the stationary contact members disposed in the rear of the stationary carrier 40. The panel also has lower terminals 202 to which leads of the multi-phase circuitare adapted to be connected.

Suitable switch overload responsive'means as the thermal relays 204 are remo'vably received between the terminals I98 and 202 and are adapted to open the switch upon overload'by de-energizing the holding coil I12, as is common practice. Said panel is provided with pilot terminals 205 which are adapted to be connected The switch thus described is "simple in construction', ismade mainly of stamped and molded parts; can be assembled rapidly ndcan be disassembled without the needof tools other than a screw driver or pliers.

I claim: v

1. In an electric switch, stationarily supported contact members, a movable plate having a plurality of movable contact members, a movable supporting frame whicnsupports said plate in horizontal position thereon, and switch operating mechanism arranged to move said frame between switch open and closed position, and said plate being removable horizontally from said 2. In an electric switch, the combination of a plurality of stationarily supported contact members. a frame which is movable vertically between switch open and switch closed positions, a contact member supporting plate carried by and .movable with said frame, a plurality of contact members carried thereby and movable therewith into and out of engagement with said stationarlly supported contact members, said plate being free from positive connection with said frame and adapted to be withdrawn horizontally therefrom with the contact members carried thereby and removed from the switch, and latching means releasably holding said plate in operative position on said frame. I

3. In an-electric switch, the combination of a plurality of stationarily supported contact members, a frame which is movable between switch open and switch closed positions, .a contact member supporting plate carried by and movable with u said frame, a plurality of contact members carried thereby and movable therewith into and out of engagement with said stationarily supported contact members, said plate being free from positive connection with said frame and adapted to be withdrawn therefrom with the contact members carried thereby and removed from the switch,

with said frame and adapted to be withdrawn therefrom, and having an extended handle by which it can be withdrawn, and said frame having means which guides saidplate for movement horizontally off and on said frame.

5. In an electric switch, a movable contact structure including a frame which is movable between switch open and switch closed positions and which has a track provided with an open end, and a contact carrying plate slidably received re-, movably on said track, said plate having contacts on its upper face and having means by which it can be pulled off the open end of said track for the inspection of said contact members and then shoved back in to operative position.

6. In an electric switch, a movable contact structure including a frame which is movable between switch open and switch closed position and hasinwardly directed spaced arms providing a track, and a contact supporting plate having opposed grooves in which said arms are received and by which said plate is supported removably on said frame and is slidable along the tracks thereof.

.7. In an electric switch, a movable contact structure including a frame which is movable between switch open and switch closed positions and has inwardly-directed spaced arms providing a track, a contact supporting plate having opposed grooves in which said arms are received and by which said plate is supported removably'and slidably-on said frame, and means releasably securing said plate in operating position on said track.

8. In an electric switch, a movable contact structure including a frame having opposed upstanding side walls provided with spaced inwardly directed parallel arms which constitute a track, an insulating contact supporting plate having opposed parallel grooves in its opposite side faces in which said arms are slidably received and from which said plate can be withdrawn, and means to secure said plate releasably in the aforesaid relation.

9. In an electric. switch, a movable contact structure including a frame movable between switch open and switch closed positions having upstanding side walls each of which has a pair of parallel slots therein, and supporting and guiding means for said frame having parallel tracks which are received loosely within said slots and constitute means to suide'said frame in parallel lines between switch open and switch closed positions.

structure including a contact supporting frame which is movable between switch open and switch closed positions and has opposed upstanding side walls each of which is provided with a pair of parallel slots therein, and supporting. and guiding means for said frame including a pair of stationary plates located at saichside walls having inturned parallel arms which are received loosely within said slots and constitute tracks which guide said frame by sliding it along said tracks to move in parallel lines between switch open and switch closed positions.

11. In an electric switch, a movable contact supporting structure comprising a frame consisting of a horizontal plate having upwardly reflexed parallel side walls the upper ends. of which are reflexed inwardly to provide a pair of spaced horizontal tracks, a movable contact-member-supporting plate having parallel grooves in its op-' posite end faces in which said tracks are located, contact members carriedby said plate, said plate adapted to be withdrawn from said frame, removable means securing said plate in its operative position on said frame, said upstanding side walls of said frame each having a pair of parallel vertical grooves therein, and supporting and guiding means for said frame including a pair of stationarily supported plates located at said side walls of said frame and each having a pair of spaced inwardly reflexed arms which are received loosely within said grooves and constitute tracks along. which said frame is guided for movement in parallel lines between switch open and switch closed positions.

12. An electric switch having the combination of a stationarily supported horizontal plate, stationary contact members carried thereby, a vertically movable horizontal plate, movable contact members carried thereby on the upper face thereof, supporting means for said movable contact members including spring supporting pins which extend through said plate and project beyond the bottom face thereof, and a supporting frame which carries said movable plate which is verticaily movable toward and away from said sta-. tionary plate and has a bottom wall which underlies said movable plate and is said extended ends of said pins.

13. In an electric switch, stationarily supported contact members, and a movable contact structm'e including a base, movable contact members carried thereby, a supporting frame which carries said base consisting of a plate which underlies said base and has upstanding side walls which overlie the ends of said base and have removable connections therewith, said plate having downwardly extended cars at its ends adiacent the side walls. and dual switch operating linkages each connected pivotally with a separate one of said ears.

14. An electric switch including a supporting frame having a pair of spaced side plates, an insulating plate overlying the upper ends of said side plate and fixed rigidly thereto, stationary contact members carried on the lower face of said insulating plate, a movable insulating plate located between said side plates and below said stationary plate, movable contact members carried by said movable plate, a movable supporting frame which carries said movable plate, said movable plate having means by which it can be switch, and an insulating plate constituting a terminal base secured to the front faces of said withdrawn horizontally from a supporting relation on said frame in the open position of the 6 spi er? side plates and terminated beneath said movable plate in-the switch open position thereof whereby said movable plate can be withdrawn ireely above the top of said terminal plate.-

15. An electric switch including a supporting 'irame having spaced side plates; a stationary insulating plate overlying the top of said side plates and secured rigidly thereto, the-lower ends of also having at their lower ends other inwardly reflexed ears, and a switch operating electromagnet core disposed between said side plates and fixedly connected with said other ears.

16. An electric switch having stationary and 5 movable contact members, a movable and removable supporting frame for said movable contact members having a locking recess therein, anda switch frame having a locking projection which is adapted to enter said locking recess in certainilo positions or said supporting frame and lock it against removal. g

GEORGE w o'mm.

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