US1762604A - Electric switch and contact structure therefor - Google Patents

Description

.June l0, 1930.

c. n AlNswoRTH ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR Filed Dec. 27, 1921 z sheets'sheet l n Ik Jiffy. 6. jrwe/vof'. .30C/Lx D. WCW-.Jai

June l0, 1930. c. D. AlNswoRTH ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR 2 Sheets-Sheet 2 Filed Deo. 27, 1927 #111m j' .M 3o

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Patented June '10, 1930 UNITED y ,s'rxrufs nPATEN'I- OFFICE CHESTER D. AINSWORTH, OF WOLLASTON, MASSACHUSETTS, ASSIGNOR TO CONDIT ELEC- TRICAL MANUFACTURING CORPORATION, 0F SOUTH BOSTON, MASSACHUSETTS, A

CORPORATION 0F MASSACHUSETTS ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR f Application led December 27, 1927. Serial No. 242,666.

This invention relates to electric switches and contact structures therefor.

In the usual electric switch, consisting of a pair of vertical insulated studs adapted to be connected at the bottom by a vertically movable bridging member, the magnetic flux surrounding the studs and bridging member, when the switch is traverse by heavy current, tends toforce apart the cooperating contact members of both or at least tends( to reduce the contact pressure therebetween and thus to cause heatin and burning of the contacts. It is an ob]ect of this inven-l tion to provide an arrangement of contact members and associated conducting components by which the conducting coin-r ponents are caused to react magnetically and to apply a force on the contact members tol urge them together when the switch is traversed by a heavy current, thusto oppose the oppositely acting ma netic reactions of the current in the genera yswitch circuit on the contact members.

A further object of the invention is the.

provision of a movably supported contact member and conducting means associated therewith arranged to set up magnetic forces acting on the contact member in a direction to urge it against its cooperating contact member. U

A further object of the invention is the provision of a movably supported contact member and a conducting component forming a conductin,"y loop of which saidcontact member is a part, the magnetic forces in the loop reacting on the contact member \to urge it ina circuit closing direction. n

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

Fig. 1 is a side elevation of the contact structure of an electric switch embodying the invention.

Fig. 2 is an end view of the Structure of Fig.` 1. A

Fig.' 3 is a section along line 3-3 of Fig. 1.

Fig'. Lis a vertical sectional detail through gne of the movably supported arcing memers.

vFig. 5 is a pers ective view of the conducting support o the arcing members.

Fig. 6 is a perspective sectional detail i1- lustrating the manner of pivotally securing a contact member to the conductin support.

Fig. 7 is a perspective view cfg the supporting'bracket' for the conducting support.

Fig. 8 is a view similar to Fig. 4 and shows therelative directions of the current in the parts. l

Fig. 9 is a vertical elevation of a modified arrangement of contact members embodying` this invention.

ig. 10 is a view similar to Fig. 4 but illustrating the modified form of contact member.

The switch here shown includes a pair of vertical conducting rods or studs 10 supported in insulators 12. The studs at the1r lower end each carry brushes 14 made up of a series of superim osed laminations the Shanks of each of w ich is surrounded bya metal jacket 16. The stud is passed through the shank and has lnuts 18 and 2O screw threaded thereon which serve to clamp the brush Xedly to the stud. The lower nut 18 has a fiat bottom contact face vand comprises a.,stationary arcing member of the switch. `The movable switch member includes a bridging member 22 whichxcomprises a conducting member of channel shape having atop flat contact face 23 and depending webs 24 and is adapted tol be .on the lower end oan insulated liftingv or switchL rod 2 6. An inverted channelsup' porting frame 27 having the at top wall 28 and the depending legs 30 is clamped to the screw threaded lower end 32 of the lifting rod under said loosely supported bridging member 22 and between its depending webs 24 thereof and hasplaterally-extended struck-out tabs 34 which are adapted to lie close to the inner faces of said depending webs to hold said bridging member from undue lateral or angular displacement on the lifting rod. A rigid conducting support 36 is disposed within said channel supporting frame 27 and comprises a flat bar which is received against the under face of the top wall 28 of the supporting frame and is secured thereto by screws 38. Said bar is extended outwardly in both directions beyond said frame and has downwardly extended end sections 40 and inwardly directed lower sections 42 which are parallel with and are spaced below the top section and has upwardly extended end sections 44 which are terminated beneath and out of contact with the horizontal top section. The end sections 40 have vertical slots or openings 46 therein. The vertical rear sections have notches 48 therein which provide upstanding projections 50 at the sides of the notches. The auxiliary contact members each comprise a stiff bar 52 of conducting vmaterial having an.upturned outer end 54 to which an arcing member 56 is secured detachably by means of a bolt 58; and said arcing member is arranged to bear against the under face of the stationary arcing member or nut 18 when the switch is closed. The rear or inner section or shank 53 of the bar 52 is extended through one of the openings 46 in the conducting support 36 and has opposed notches 60 in its side edges at its inner end which' are received loosely in the upstanding projections 50 of the vertical and inner end 44 of the conducting support \with the end of the shank lyin loosely in the notch 48. A thin plate 62 as a notch 64 in its lower face in which the shank is received and said plate is secured to said upstanding projections 50 by screws 65 whereby to secure the contact member in pivotal engagement with the inner'section 44 of the conducting support againstv acciportion extended through the opening 46.

of the conducting support and thus serves sulating sleeve and serves to urge the contactl member upwardly. vWhen the switch is closed the" spring is adapted to be compressed as shown in Fig. 1 and the contact member is adapted to float upon the spring.

The arrangement of the conducting support 36 and the contact member forms a conducting loop which causes the movable Contact member to be forced against the cooperating stationary contact member -in dependently of the spring 74'when current flows through the auxiliary current conducting path. Fig. 8 illustrates the instantaneous direction of the current through the auxiliary current-conducting structure wherein the current is in the direction of the arrow a, inwardly or from the Contact member through the shank thereof to the inner end of the bottom horizontal section 42 and in the opposite direction in said section outwardly toward the vertical section 40 and upwardly through said vertical section to the end of the top section 36 and inwardly toward the left in said section as indicated by the arrow d to the similar contactme1nber on the other side thereof. As

`the same direction in the shank 53 and in `the upper horizontal section 36 and thereaction therebetween thus tends to draw the contact member upwardly so that both the upper and lower sections 36 and 42 respectively act on said contact member in a direction to force it upwardly and against the cooperating stationary contact or arcing member 18. Since the sections 36 and 42 are close to the contact member their magnetic reactions on the contact member can be made great enough to offset the oppositely-directed reaction between the contact. member and the studs. A,

A pin 82 is extended through the webs 30 of the supporting frame 27 and lies within and close to the angle between each lower horizontal section 42 and the inner upstanding end 44 of the conducting support and is insulated therefrom by the insulating sleeve 84 and the washers 86 Fig. 2 and serves to support the lower horizontal section against upward displacement due to the" fulcruming of the contact member on the spring 74 when the switch is in closed position and also to prevent the lower horizontal section from being displaced in a downward direction by the magnetic reac tion of abnormal currents. Said section, if displaced downwardl brings the shank 53 of the contact mem r against the insulating sleeve of said pin 82 and thus forces the arcing member 56 thereof with increased effect upwardly against the cooperating stationary arcing member.

In the modification shown in Fig. 9, the movable contact member 87 is vertically disposed and has it upper end in contact with the depending stationary arcin member 88 and has its lower end 90 pivota ly connected with avertically extended rigid conducting member 92 and electrically connected therewith by a loop of flexible braid 94. The contact member 87 and the conductor 92 cooperate to form the legs of a U-shaped conducting path, the current in the legs being in opposite directions, so that the contact member 87 is forced outwardly into pressure contact with its arcing member 88 with a force greater than that resulting from the compression spring 96 alone. In this modificatlon, the magnetic reaction of the current in the switch studs complements the magnetic reaction in the U-shaped conducting path.

The modification shown in Fig. 10 is similar to that shown in Figs. 1 through 6,

with the exception that the arcing member 56a carried by the shank 52a extends freely through a hole 98 in the upper horizontal section 36a of the conductin support for engagement with the cooperatlng stationary contact 18. In this case, the opening 98 is the equivalent of the opening 46 of the previous figures. The current reactions in the modification shown in Fig. 10 are the samey as described in connection with Fig. 8.

I claim:

1.- In anelectric switch, the combination of fixed switch terminals having contact members at their ends, movable contact members cooperating with said fixed contact members so arranged `that the current traversing the general switch circuit tends to separate Said contact members, and relatively movable conducting elements included in said switch circuit which `react independently and in op osition to the general switch circuit to hold) said contact members together. 4

2. In an electric switch, a contact member. a cooperating movable contact member, and a looped conducting member connected with said movable contact member and having relative movable parts disposed in position to react magnetically in a direction to urge said contact members together.

3. In an electric switch, a contact member, a cooperatin movable contact member having an exten ed current-carrying arm., and a conductor connected electrically with the end conducting loop terminated in a movably supported contact member, and a second contact-member cooperating therewith, the magnetic reactions of the current in said loop acting to force said movably supported contact member against said other contact member.

6. In an electric switch, a contact member, a conducting member, and a second contact member extended generally parallel and lying close to said`conducting member and having a connection at one end therewith by which said contact member is movable toward and away from said conducting member, the magnetic reactions of the current traversing said movable contact member and conducting member being in a direction to urge said movable contact member toward said other Contact member.

7. In an electric switch, a rigid conducting member, a contact member overlying and disposed close to said conducting member and having a flexible connection at one end therewith by which current ltraverses said contact and conducting members in opposite directions, and a second contact member cooperating With said first contact member.

8. Inan electric switch a contact member, a cooperating contact member disposed beneath said first contact member having an angularly-extended conducting .and supporting arm, and a conducting member disposed beneath and close to and generall parallel with the angularly extended arm o said contact member and having an electrical connection therewith at the end of said arm opposite said contact member.

9. In an electric switch a contact member, a cooperating contact member disposed beneath said first contact member, and a conducting member disposed beneath and close to and generally parallel with said contact member and having a connection at the end of said contact member and forming a magnetic loop therewith, and a spring urging said second contact member towards said first contact member.

10. In an electric switch a contact member, a cooperating contact member disposed beneath .said first contact member, and a conducting member disposed beneath and close to and generally parallel with said second contact member and having a connection at the end of said Contact member and formino` a magnetic loop therewith, and an insulated spring bearing against said conducting member and said second Contact member.

11. In an electric switch, a movable contact member, means providing a current path on opposite sides of and close to said contact member, and a cooperating contact member disposed in position to be engaged forcibly by said movable contact member due to the current reactions between it and said conducting path.

12. In an electric switch a movable contact member, means overlying and close to and in series with said contact member providing a current path in the same direction as in said contact member, and a cooperating contact member disposed in position Vto be pressed against by said movable contact member due to the magnetic reactions between it and said current path.

13. In an electric switch, a conducting member having closely spaced upper and lower parallel conducting sections through which current is adapted to pass in opposite directions, and a movable contact mem'.- ber(extended in the length of and disposed between said conducting sections and adapted to be traversed by current in a path generally parallel to said sections.

14. In an electric switch, a. rigid conducting member having upper and lower closely spaced parallel sections connected at their outer ends, a contact member disposed between and extended in the direction of the length of said upper and lower section and having a iexible connection with the inner end of said lower section.

15. In an electric switch, a contact structure comprising a rigid conducting support having upper and lower parallel and closely spaced conducting sections connected at their outer ends, an arcing member extended through .said support between said sections and in the direction of the length thereof, and having an electrical connection therewith at the inner end\of said lower horizontal section.

16. In an electric switch, a rigid conducting support having upper and lower closely spaced parallel conducting sections having a connection at their outer ends, saidlower section having an up-standing lower end, a

contact member extended freely through said f connection and insulated therefrom and extended into the space between said upper and lower sections and having a flexible connection with said upturned inner end, and an insulating spring carried by said lower secion and bearing against said contact mem- 17. In an electric switch, a rigid conducting support having upper and lower closely spaced parallel conducting sections having a connection at their outer ends and an opening in said connection, a contact member passed freely through said opening into the space between said sections and extended in the direction of the length thereof, and an insulating sleeve surrounding said contact member in-said opening, the inner end of said lower conducting section being upstanding and the inner end of said contact member having a pivotal connection therewith.

18. In an electric switch, a conducting support having upper` and lower closely spaced parallel conducting sections having a connection at their outer ends with an opening in said connection, a contact member passed freely through said opening into the space between said sections and extended `in the direction of the length thereof, an insulating sleeve surrounding said contact member in said opening, the inner end of said lower conducting section being upstanding and the inner end of said contact member having a pivotal connection therewith, and a compression spring carried by said lower section bearing against said insulating sleeve.

19. In an electric switch, a conducting support comprising a horizontal bar reflexed to provide upper and lower closely spaced horizontal sections and an outer vertical vend connection section and an upstanding inner free end at said lower section, a contact member extended into the space be,- tween said sections in the direction of the lengths thereof and having a ivotal connection with said upstanding en and means to restrain the free inner end of said lower section against undue displacement.

20. In an electric switch, a conducting support comprising a horizontal bar reflexed to provide upper and lower closely spaced horizontal sections and an outer vertical end connection section and an upstanding inner free end at said lower section, a contact member extended into the space between said sections in the directionV of the lengths thereof and having a pivotal connection with said upstanding end, and a fixedly-supported insulated bar disposed below said contact member and 'above said lower section at the free end thereof.

21. In an electricswitch, a movable switch member comprising a lifting rod, a horizontal conducting member carried by said rod at the bottom thereof, a supporting frame comprising an inverted channel member carried by said rod beneath said conducting member, a conducting support comprising a horizontal bar fixed in the channel of saidvchannel member and having oppositely extended ends providing upper and lower horizontal closely spaced sections connected at their outer ends, the inner ends of said lower sections being free, and arcing members disposed beyond the ends of saidy conducting support and extended into the space between said upper and lower sections and along the lengths thereof and having lexible connections with thefree inner ends of said lower section.

22. In an electric switch, a movable switch linember comprising a lifting rod, a horizontal conducting member carried by said rod at the bottom thereof, a supporting frame comprising an inverted channel member carried b f ysaid rod beneatl1.said Conducting member, a horizontal eonductiner bar lixcd in the channel of said channe member and having oppositely extended endsy providing upper and lower horizontal closely siaced sections connected at their 'outer en s, the inner ends of said lower sections being free, and contact members disposed beyond the ends of saidconducting sup )ort and extended into the space between `sal upper and lower sections and along the tact member, a movable ctntaet member cooperating therewith, and a solenoid having relatively movable conducting elements connected with said movable contact member disposed to react magnetically by the current `traversing them in a direction to urge said movable contact member against said stationary contact member.

In testimony whereof, I have signed my name to this specification.

CHESTER D. AINSWORTH.

in the channel of lsaid channel member and y having oppositely extended ends rovidin upper 'and lower horizontal close y space sections connected at their outer ends, the inner ends of said lower sections being free and upstanding, and outstanding ,contact members located beyond theends of said conducting support and extended into the` space between said upper and lower sec l' tions and having ivotal connections at their inner endswith t e upstanding ends of said lower sections, and insulated pins carried by and extended between the webs of saidchannel member and over the free ends of said lower sections and under the inner ends,

of said contact members. .y

24. In an electric switch, a movable switch `member comprising a lifting rod, a main bridging member com )rising an invertedl channel member carrie loosely on said rod at its lower end, and a supporting frame for the auxiliary contact members comprising an inverted channel member disposed within and laterally spaced from the webs of the aforesaid channel member and fixed to said lifting rod and having laterally extended frame-spacing, projections which are disposed close to the inner faces of the webs of said main bridging member.

25. In an electric switch, a stationary con-

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