US2426129A - Electric switch - Google Patents

Description

Allg- 19, 1947 H. l.. VAN vALKENBuRGErAL 6 Sheets-Sheet 1 edlay 6,-194'5 'r ..1 fd. ,@um@ y Q, Q WW1 n mz @Ef ,lil rli ik@ u l I /J// lq/llllllllf/ Mwwui\|\||||l||- 71. .M 14W l//lvwwn/l//// L 6 Sheets-Sheet. 2

BLBGTRIG SIITGH Filed By 6. 1945 H. L. VAN VALKENBURG ETAL- Il Illv I Aug. 19, 1947.

Aug. 19, 1947. H. l. vAN'vALKl-:NBURG ErAL v2,426,129

ELECTRIC SWITCH Filed'uay 6. 1945 e sheets-sheet s El fr.

NJRS. C u feti: )y UM- AITORNEY H. L. VAN VALKENBURG ETAL BLBCTRIG- S'ITGH Y med my e. 194s 6 Sheets-Sheet BY ie/*Z E 5E/9de): ATTORNEY Aug. 19, 1947. H. l.. VAN VALKENBURG ETAL 2,426,129

ELECTRIC swI'rcH l Filed may 6, 194:' e sheets-sheet 5 '23E-:+1111 lix Herr/von )(1,7

ATTORNEY Aug. 19, 1947. H. VAN VALKENBURG ETAL 2,426,129

ELECTRIC SWITCH Filed May 6, 1943 e sheets-sheet e NT ORS.

Her/77a ATTORNE Patented Aug. 19, 1947 ELECTRIC SWITCH Herman L. Van Valkenburg, Wauwatosa, and Carl A. Schaefer, Whitefish Bay, Wis., assignors to Square D Company, Detroit, Mich., a corporation ot Michigan Application May 6, 1943, Serial No. 485,794

(Cl. 20o- 116) 19 Claims. 1

This invention relates to electric switches, and more particularly to electric switches manually operable at will to open and closed positions and automatically operated to open position in response to current overloads, such as are used for the protection and control o! electric motors.

An object of the invention is to provide a manual and automatically operable electric switch having an improved and reliable operating mechanism for the manual and automatic operation.

Another object of the invention is to provide an automatic and manually operable electric switch having current responsive means in a plurality of poles, and a latched tripping member in which occurrence of a current overload in any one of said current responsive means will effect unlatching of the tripping member from the plurality of current responsive means.

Another object of the invention is to provide a manually and automatically operable electric switch in which the operating mechanism includes an operating part normally latched for movement in a restricted path for manual operation and with the operating part releasable on overload for automatic movement out of said path to effect opening movement of the switch.

Another object of the invention is to provide a manually and automatically operable electric switch in which the operating mechanism includes a double toggle arrangement with one of the toggles effective for manual operation and with the other toggle releasable upon the occurrence of a current overload to eiect automatic tripping of the switc Other objects and features of the invention will be readily apparent to those skilled in the art from the speciilcation and appended drawings illustrating certain preferred embodiments in which:

Figure l is a plan view of the electric switch according to the present invention with parts broken away and with the enclosing box removed.

Figure 2 is a vertical sectional view on the line II--II of Figure 1, showing the parts in manual ofi position.

Figure 3 is a sectional view in a plurality of planes along the lines III--Ill in Figure 2.

Figure 4 is a sectional view in a plurality of planes along the lines IV-IV of Figure'2.

Figure 5 is a partial detail sectional view on the line V--V of Figure 4.

Figure 6 is a partial view similar to Figure 2 showing the mechanism in the contacts engaged position.

Figure '7 is a partial sectional view similar to 2 Figures 2 and 6, but showing the mechanism in automatically tripped position.

Figure 8 is a partial sectionalview similar to Figure 6, but showing a slightlymodifled form of the invention.

Figures 9, 10 and 11 are diagrammatic views showing, respectively, the on, off and tripped positions of the mechanism of Figure 8.

Figure 12 is a partial sectional view similar to Figure 6, but showing a further modified form of the invention.

Figures 13, 14 and 15 are diagrammatic views showing, respectively, the on, ofi" and tripped positions oi the mechanism of Figure 12.

The electric switch according to the present invention comprises an insulating base I upon which the conducting parts and operating mechanism are mounted. Against the bottom face of the insulating base is disposed an insulating ber sheet 2 and upon the opposite side of the fiber sheet 2 is a metallic mounting plate 3 rigidly secured to the base l by studs 4, mounting plate 3 being rigidly secured to the back wall 5 of an enclosing box by the studs 5. At the uppr or switching end of the base I, within recessed chambers in the base, are mounted conducting straps 1, shown more particularly in Figure 2, carrying at their front ends terminal portions 8 for the connection of circuit wiring and with their back portions carrying contacts 9. The conducting straps are rigidly secured to the base by studs I I and the portions 8 are provided with terminal screws I2. For each pole of the frame there is provided an additional stationary contact I3 mounted upon conducting straps I4 in the case of the two outer poles and upon conducting straps I5 in the case of the two inner poles., The conducting straps I4 extend forwardly and end in terminal plates I5 adapted for connection to the current responsive overload units to be connect ed in the two outer poles of the switch. At the bottom of the base are mounted circuit terminals I1 for the outer poles and I8 for the inner poles of the switch. The terminalsv I1 extend inwardly into spaced relation with the bars I-6, also for connection to the current responsive units, and the terminals I8 extend downwardly into engagement with the conducting straps I5. The stationary contacts il and I3 are bridged by a conducting plate I9 carrying contacts 2l and 22. The plates I9 being mounted for movement within guides 23 containing contact pressure springs 24 biasing the switching plates I 9,

The currentrresponsive units comprise insulatiing body portiongfwithin which are secured elongated v4cylindrical posed shafts 21l ratchet wheels. About the elongated cups' 2C 4 4 Dort the Plate 84 in its forward position withvthe ups' 231x; Vwhich are dis# at their.

are insulating spools 29 about whichfarewound--v resistance heating elements 3|. The opposite-interior ends oi the body portions 2l are provided with conducting elements 32 to which the opposite ends of the resistance heating coils 3| are drlcal spacer 33 is provided at an upper corner oi the plates and a pair oi outer insulating sheets 33 interlock with the ears 31 to maintain the assemblage of plates 35 and 38, these insulating 39 and the cylindrical spacer 3l being maintained in an insulating cross bar 45 by means of a, stud 48. The cross bar 45 is provided with a projecting post 41 for each pole oi' the breaker and upon the post 41 are mounted the guides 23 for the bridging contact plates I9. It is thus seen that rotate about the pivot 42.

A main operating spring 48 is disposed between the bottom plate 38 and the arms 43 and biases the arms at all times for rotation in a clockwise direction to move the contact plates I9 to the contacts disengaged position.

Also mounted upon the pivot pin 42 by a spacer bearing 49 in a bell crank lever 5I having one end pivoted at 52 to a link 53, the opposite end of the bell crank I being disposed loosely within a slot in a iloating insulating plate 54, guided for movement within slots 55 in the plates 35 and 39. The frame plates 35 are provided with integral extensions 5B bridged by a pin 51 to which is secured one end of a tension spring 58, whose other opposite ends of the plate I4 are provided with latch elements 59 carrying latching projections 6I adapted to engage with and be retained by the teeth on ratchet wheels 2l. As more particularly shown in Figures 3 and 4. the ratchet wheels 23, when in normal nonrotating condition, will supbelrcrank tl latched in its position-of maximum clockwise rotation at the outside i the mme pistes as, by means esame.

on" position oi the switch mechanism as in Figure 6. 'I'he links I1. 39 and 12 in eirect form a an automatic opening operation.

The toggle formed by the links t! and 12 is normally maintained in the relationships shown in Figures 2 and 6, by means ot link 53 which interconnects the pivots 1I and 52. 'I'he bell crank 5I is normally maintained stationary due to the maintenance of plate 54 in latched position by the ratchet wheels 28 and, accordingly, the pivot 52 is normally maintained in a :llxed position; hence, the pivot 1I is limited in its mo- 42 as a center.

In the manual wardly in an arc about pivot 42. Link 88 will, thereupon, force pivot 1| downwardly in an arc about pivot 52; link 12 will thus eilect rotating of the contact operating arms 43 in a counterthe circuits through me poles of the switch. This movement of the operating handle 64 is stopped.

tion of Figure 2 under the bias exerted by the spring.

Upon the occurrence of an overload through either or both of the heating coils 3l. the associated tripping unit will become active through the softening ofits holding alloy and permit rotation of the associated ratchet wheel 28. As this ratchet wheel rotates, the associated latch 6| moves downwardly out of engagementr therewith, permitting counterclockwise rotation of the bell crank 5I. As this movement continues, the plate 54 is rotated and the unlatched latching portion 6i will be moved sideways toward the interior axis of the switch until it is disengaged from its associated ratchet, whereupon the plate 54 moves bodily toward the back of the base carrying the bell crank 5I to its maximum counterclockwise position, as shown in Figure '1. This movement of the bell crank moves the pivot 52 toward the left and collapses the toggle formed by links 69 and 12 into the position of Figure '1, the contacts separating underthe action of the main spring 48 and the trip latch spring 58.

In this movement of the parts to the automatically tripped position with the collapse of the linkage 69-12, a small biasing force is exerted on the operating handle to. move it' a short distance in aclockwise direction to aposition intermediate its on and =off positions in which it indicates the automatic openingof th'e circuit.

It is apparent that since the toggle represented by the link 69--12 is not fully made, the mechanism will operate to open the contacts if thev main spring 48 is made sufiiciently strong and the spring 58 is omitted entirel However, to speed up the opening movement of the switch mechanism and to make this operation more reliable, the biasing spring 58 to more positively collapse the toggle is utilized.

The insulating body portions 25 of the operati-'J ing units interlock with the base l, as shown, to form chambers about the resistance coils 3| which are closed against egress of flame occurring upon the burning out of these coils except for a vent 11 leading through the base and venting to the exterior at the sides thereof adjacent the back. The burning out or fusing of the resistor coils may occur upon occurrence of a heavy sh'ort circuit through the switch which the attendant fuses may not clear with sufficient speed to prevent damage to the resistors. With the arrangement shown, the vapor and flame which result from such burn-out are successfully vented without the emission thereof to the outside of the box enclosing the switch.

With the parts in the automatically tripped position of Figure '1, it is necessary to reset the switch mechanism by relatching the plate 54 in its forward position before the contacts may be manually closed. This `operation is effected by moving the switch handle. 84 to the off position in a clockwise direction from the position shown in Figure 7 to th'e position of Figure 2. 'in this movement, a spacer 66 engages the surface 1B on the lever 53 and moves this lever toward the right, thus rotating the bell crank in a clockwise direction and moving the plate 54 forwardly until the latches 6l engage with the ratchet wheels 28 at the opposite sides of the switch. Assuming that the alloy within the tripping unit has, in the meantime, cooled sufficiently to solidify, the ratchets will be maintained in position and the plate E4 latched in its forward position. The parts then assume the position of Figure 2 and the rotation of the handle 64 in a 6 counterclockwise direction will move the bridging contacts into engaged position as previously explained.

In Figures 8, 9, 10 and 11, a slightly modified form of the invention is shown utilizing a single Operating spring and securing greater reliability of action than would be secured if the preferred form of the device were utilized without the spring 58. In this construction, the spring 58 is omitted and the link 12 is replaced by a bell crank lever 18, one leg of which performs as in the preferred embodiment the function of the link 12. The other leg of the bell crank 18 terminates in a circular portion 19 which receives the seat 8l for a main operating' spring 82 which replaces the operation spring 48 of the preferred embodiment. In this construction, the spring 82 will function as above to rotate the main Contact operating arms 43 in the manual operation and upon automatic operation, the toggle formed by the link 89 and the leg of the bell crank will be collapsed under the bias of spring 82 acting on the bell crank lever. In this construction, a single spring 82 replaces the springs 48 and 58 and the collapse of the toggle is effected not only through the force moment represented by its .position at one side of dead center position, ,but also by the force moment exerted through the arm, ofthe bell crank lever. The on, off and tripped positions shown diagrammatically inFigures 9, 10 and 11 correspond to the description of operation for the preferred form of the breaker.

Another modification of the manual and automatic switch according to this invention is shown in Figures l2, 13, 14 and 15. The principal distinction over the switch mechanism in Figures 1 through 7 lies in the substitution of a prop latch arrangement for the three-link double toggle construction shown in'the preferred form. In this arrangement, there is substituted for the link 81 a pair of parallel links 83 pivoted as before on the pivot pin 60, but carrying at their opposite l ends a roller 84 mounted on a bridging pivot pin 85 upon which is also pivoted the lever 14. For the links B9 and 12 there is substituted a single link 86 pivoted on the pivot pin 13 and having on its forward surface a trackway 81 engaging with the roller 84. The link 53 is pivoted to link 8B at an intermediate point by the pivot pin 88. The other operating parts of the switch are substantially the same as in the preferred embodiment. In the operation of the switch of Figures 12 through 15, the normal manual `movement of the pivot 88 is limited to an arc about pivot 52 by the link 53, thus maintaining the link 86 in a substantially upright position. In the manual operation, the links 83 function substantially in the same manner as the link 61. As the handle is rotated in a counterclockwise direction from the position of Figure 14 to the position of Figure 13, such rotation of the handle moves thepivot 85 of the roller 84 in an arc about pivot 42, thus moving the link 86 downwardly and rotating the main contact arms 43 in a counterclockwise direction into the contacts engaged position of Figures 12 and 13. The manual movement to off position is the reverse of that described, link 8B again being maintained in a substantially upright position but moving upwardly as the upper end of the links 83 move to the right into the position of Figure 14. In the automatic operation of this modification, the latch plate 54 is released as previously described and the bell crank 5I is rotated in a counterclockwise direction to move link 53 to the right and rotate link 86 in a counterclockwise direction 7 about pivot pin 13. In this rotation oi' the link Ii, it is moved beyond the roller 84 so as to be no longer retained thereby, whereupon the movable contacts are free to rotate in a clockwise directhe terms of the following claims.

What is claimed is: 1. In an electric switch, switching means, an

open circuit position.

2. In an electric switch, switching means, an

the main spring I8 into to be latched in a normal stationary position, positively restraining a knee e to movement in a ixed collapse said knee out of its normal xed path and eiect automa movement of the switching means to open tion.

t current flowing through position to eiect the automatic ment ot the contacts.

7. In an electric switch, stationary and movable contacts. manual means for effecting movement of the movable contacts to engaged and disengaged positions, and automatic means for e!- fecting movementl of the movable contacts to disengaged position in response to the passage of an overload current through the switch and including a pair of solder pot relays having ratchet wheels normally stationary but rotatable in response to the passage of excess current through the relays, a member bridging said ratchet wheels and normally latched thereby in fixed position, and means whereby movement of said bridging member eiects operation of the means for automatically opening the movable contacts, movement of said bridging member in response to release by oneV of said ratchet wheels effecting the mechanical release thereof from the other ratchet wheel and its movement bodily to a position eiecting operation of said automatic means.

8. In an electric switch, a switching member, an operating handle, an operating link pivotally connected to said switching mechanism, an operating link pivotally connected to said handle, a

roller on said handle link normally engageable with the link on said switching member to effect movement thereof to move the switching member to circuit controlling positions in response to movement of the operating handle, means normally restraining a point on said switching mem.'- ber link for movement in a fixed path, and cur'- rent responsive means for rendering said restraining means ineffective to effect movement of said switching member link out of said fixed path to an inoperative position to move the switching member to open circuit position.

9. In an electric switch, a switching member, an operating handle, a lever pivotally connected to said switching member, a lever pivotally connected to said operating handle, means connected to said handle lever and restricting its point of connection thereto to movement in a xed path at all times, means connected to said switching member lever and normally restricting its point of connection thereto to movement ina fixed path, interengaging surfaces on said links normally operatively engageable to effect movement of the switching member in response to movement of the operating handle for manual switching operation, and means responsive to the flow of an overload current through the switch for effecting movement of said switching member link out of operative engagement with said handle link to eiect automatic switching movement of the switching member to disengaged position.

10. In an electric switch, switching means movable in a xed path, an operating handle movable in a `fixed path, a link pivotally connected to said switching means, means connected to said link and normally restraining the point of connection thereto to movement in a fixed path, said link having a surface thereon forming a trackway, a link pivotally connected to the operating handle and having a roller on its opposite end cooperating with said track-way, means connected to said handle link and restricting its point of connection thereto to movement in a iixed path, movement of said handle moving said handle link to effect movement of the switching means to its circuit closed and circuit open positions, and means responsive to the flow of an overload current through the switch for eiecting movement o said rst mentioned link outof its normal iixed path to move its track-way beyond the roller on said handle link to eifect automatic movement of the switching means to disengaged position.

l1. In an electric switch, a switching member,

an operating handle, an operating lever pivotally connected to said switching member, an operating lever pivotally mounted on said operat- .v ing handle and directly movable thereby, means for positively transmitting force from one of said levers to the other, means for positively restraining points on said levers other than their said pivotal connection and mounting to predetermined paths -of movements, and current responsive means operable upon the occurrence of a current overload through the switch for releasing at least one o! said restraining meansto effect automatic movement of the associated point out of its predetermined path to its inoperative position, and automatically moving the switching member to open the circuits of the switch.

12. In an electric switch, a switching member, an operating handle, an operating lever pivotally connected to the switching member, an operating lever pivotally mounted on said operating handle and directly movable thereby, means interconnecting said levers, means positively restraining a point on said handle lever other than said pivotal mounting to a fixed path of movement at all times, means normally positively restraining a. point on said switching member lever other than said pivotal connection to a fixed path of movement, means for effecting movement of said leversin response to movement of said operating handle with said points positively rel strained for movement in said fixed paths to of said linkage to a fixed path of .an operating handle, a

move the switching member to open and close the circuit through the switch, and current responsive means for rendering the restraining means for said switching member lever point ineiective to permit movement thereof out of its fixed path to an inoperative position to effect automatic movement of the switching member to open the circuit through the switch.

13. In an electric switch, a switching member, an operating handle, an operating linkage interconnecting said handle and said switching member, means normally positively restraining a knee movement, means for extending and collapsing said linkage for manual operation of said switching member while said-knee moves in said positively iixed path, means for moving said restraining means to move said knee of said linkage out of said fixed path of said movement and eiect collapse thereof to automatically move said switching member, and current responsive means for rendering said means for moving said restraining means effective upon occurrence of a current overload through the switch.

14. In an electric switch, a switching member, an operating handle, an operating linkage interconnecting said handle and said switching member, a lever pivotally connected to a knee of said linkage, means providing a pivotal mounting vfor said lever about which the lever rotates to restrain said knee of said linkage to a fixed path of movement, means for extending and collapsing said linkage for manual operation of said switching member while said knee moves in said fixed path, and vcurrent responsive means operable upon the occurrence of a current overload through the switch for effecting movement of the pivotal mounting of said lever to move said linkage knee out of said iixed path of movement to eiect automatic movement of the switching member to open position.

l5. In an electric switch, a switching member, linkage interconnecting said switching member and handle, means for 9,426,129 u iixed th f t xtending and exten and collapsing said linkage upon manpa o movemen means e ual mciiiilrlegment of said operating handle to move collapsing the linkage in response to movement the switch member and perform the switching oi' said operating handle to move said knees in operation. meansblasinga knee oi' said linkage for said ilxed paths to eii'ect movement of said movement to collapse the linkage. and current s switching member into its operating positions. responsive means normally positively restraining -and means operable upon the occurrence o! a said knee from said collapsing movement and current overload through the switch for eii'ecting normally positively limiting the knee to a Predemovement of the pivotal mounting of said second tei-mined path of movement during lmanual opermentioned lever to move the associated knee out ation o! the switch. said current responsive 10 oi' its normal nxed path to collapsed position to means upon the occurrence of a predetermined eii'ect automatic opening movement of the switchcurrent overload through the switch eiiecting the ing mm1- release of said knee for movement out of said 19. In an electric switch. a switching member predetermined path under said biesing means t0 mounted for oscillation about a xed pivot, an etrect automatic Opening of the circuit through 15 operating handle mounted for oscillation around the switch. -a nxed pivot. a multiple linkage interconnecting 16. In an electric switch. a switching member. said switching member and operating handle. a an Operating handle. a linkage intercnnnedtins lever pivotally connected to the link adjacent to said switching member and Operai-ins handle. the operating handle and having a fixed pivotal means for extending and collapsingsaldlinkagein go mounting about which it rotates to limit moveresponse to manual movement of said operating ment of the gdjnnt linkage knee to o aged handle to perfnrm the Switching operation. means path at all times, a lever pivotally connected to the biasing a knee of said linkage towanl a collapsed link adjacent the switching memberand having position. a lever pivetally mected t0 Seid hee a normally iixed pivotal mounting about which it and having a normally xed plVOt lbwt which zo rotates to normally limit the adjacent linkage it rotates to restrain said knee from collapsing `knee to a ilxed path oi' movement, means for movement. and current responsive means for efmoving said linkage in response to movement of fecting movement of said lever mounting to Per* said operating handle to eil'ect movement of mit collapse of the knee under said bias P011 said knees in said ilxed paths to manually thewl're'nce 0f d ment Uvel'ld thmuh the 30 move the switching member to circuit closed :Kitch t0 @am lutomtic Opening 0f the circuit and circuit open positions and current reponsive 17. In an electric switch. e Switchin member' mounting of said second mentioned lever to peran operating handle. a multiple llnkse @mulls mit movement of the associated linkage knee to said switching member and operating handle, 35 collapsed position to um means for collapsing and extending said linkage to eiect movement of said switching member in therethrough response to movement of said operating handle to eifect the switching operation. levers pivotally mole v vAIKmURa cnnneetedtokneesoi'saidlinkageandhavingo CARLASIHAnN'El-h pivotal mountings about which they rotate to restrict said knees to iixed paths oi' movements, REFERENCES CITED and means for en'ecting movement ci at least une of sam lever mountmgs toenect movement of 'Ihe following references are of record in the at least the associated knee out of its ilxed path me 0f this tenttoacollapeedpositionupontheoccurrenceofa UNITED TENTS current overload through the switch. whereby to STATES PA eil'ect automatic opening of the circuit. Number Name Date 1s. In an electric switch. a switching member, 2,001,513 Zurcher May 14, 1935 an operating handle. a multiple linkage inter- 5o Y 2,134,613 Johnson Oct. 25, 1938 connecting said switching member and said 2,214,695 Jennings Sept. 10, 1940 operating handle, a lever pivotally connected to 1,971,732 Raney Aug. 28, 1934 the knee of said linkage adjacent to the operating 2,126,412 Rowe Aug. 9, 1938 handle and having a nxed pivotal mounting about 2,257,477 Newton Sept. 30, 1941 which it rotates to limit said knee to a fixed path 55 2,308,244 Butler Dec. 22, 1942 of movement at all times. a lever pivotally con- 2,119,459 Guett May 31, 1938 nected to the knee o! said linkage adjacent to 872,513 Hewlett .f Dec. 3, 1907 said switching member and having a normally 991,511 Johnson May 9, 1911 4fixed pivotal mounting about which it rotates to 2,203,131 Coy June 4, 1940 normally limit said second mentioned knee to a .o 2,289,179 Coy July 7, 1942

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