US3242286A - Circuit breaker linkage having a toggle link of variable length - Google Patents

Circuit breaker linkage having a toggle link of variable length Download PDF

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Publication number
US3242286A
US3242286A US246699A US24669962A US3242286A US 3242286 A US3242286 A US 3242286A US 246699 A US246699 A US 246699A US 24669962 A US24669962 A US 24669962A US 3242286 A US3242286 A US 3242286A
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contacts
link
links
toggle
group
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US246699A
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Raymond B Heilman
Harold H Bahr
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Heinemann Electric Co
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Heinemann Electric Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/50—Manual reset mechanisms which may be also used for manual release
    • H01H71/52—Manual reset mechanisms which may be also used for manual release actuated by lever
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H73/00—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism
    • H01H73/36—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism having electromagnetic release and no other automatic release
    • H01H73/38—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism having electromagnetic release and no other automatic release reset by lever

Definitions

  • a still further object is to provide a movable contact arm connected to a linkage, the movable contact arm being provided with an improved, simplified arrangement to roll and slide the movable contact (during opening movement of the arm) and abruptly move it so as to break any bond that may have formed between the contacts for facilitating the opening of the contacts.
  • a circuit breaker is provided with a pair of separable contacts, one of the contacts being mounted upon a movable contact arm, the latter being pivotal from a contacts closed position to a contacts open position and suitably biased by a spring to the open contacts position.
  • a iirst or handle toggle group of links is provided including a vhandle link connected lto a second link of varying length and together ⁇ jointly forming a toggle.
  • a second or main toggle group of links is also provided, the main toggle group of links 4being connected by an insulator coupler link to the handle toggle 4group of links.
  • the main toggle group of links comprises toggle links one of which is connected 'to a catch link and the other to the movable contact arm.
  • the coupler link is connected to the knee of the main toggle and the catch link is controlled by ya rockable cradle and an electromagnetic means.
  • Suitable stop means are provided for the handle toggle corresponding to the contacts closed and contacts open positions.
  • the main toggle is provided with means for 'limiting its overcenter travel in the contacts closed position and, further, the movable arm is provided with a stop pin for limiting its movement in the contacts open position.
  • the handle toggle In the contacts open position, the handle toggle is locked in an overcenter position by a spring carried by the link of varying length which also locks the handle 'toggle in an overcenter position when in the contacts closed position, but on the ⁇ other side of the toggle center line. Also, 'in the closed position of the contacts the main toggle links are locked in the overcenter position by the bias of the movable contact opening spring.
  • the coupler link transmits the manual force at the handle (during manual opening and closing) 'to the main toggle, as well a's vtransmitting an initial resetting force from the main toggle to the handle toggle, but when the handle and main toggles are at rest in the closed position of the contacts they are stable independently of each other and of the coupler link which connects them. Therefore, :it
  • FIG. l is a view, partly in section and partly in elevation, of a circuit breaker incorporating this invention with the linkage illustrated in the contacts open position;
  • FIG. 2 is a view similar to FIG. 1 of the same circuit breaker but illustrating the contacts closed position and taken along the line 2 2 in FIG. 8;
  • FIG. 3 is a view similar to FIG. 2 but illustrating the position of the linkage when the circuit breaker is tripped electromagnetically and a force is applied to the handle preventing the handle from automatically moving to the contacts open position, that is, the trip free position;
  • FIG. 4 is a sectional view taken along the line 4 4 in FIG. 3 but part of the suspension structure for the movable tube has been broken away for illustrative purposes;
  • FIG. 5 is a partial view ltaken along the line 5 5 in FIG. 4 but in FIG. 5 some of the suspension structure is illustrated which is not illustrated in FIG. 4;
  • FIG. 6 is a partial, perspective view illustrating part of the linkage in the contacts closed position
  • FIG. 7 is a view, partly insection and partly in elevation, for the position of the mechanism illustrated in FIG. 2 with the outer case broken away to better show the relation of the mechanism to the frame plates supporting it;
  • FIGS. 8, 9, and 10 are sectional views taken along the lines 8 8, 9 9 and 10 10 in FIG. V7;
  • FIG. 1l is a top view taken along the line 1v1 11 in FIG. l lbut showing the movable tube in elevation;
  • FIG. l2 is a diagrammatic view of the linkage after electromagnetic tripping and upon initial movement of the handle toward the contacts open position but prior to com-plete automatic resetting of the mechanism when no force is applied to the handle tending to hold it in the contacts closed position.
  • a circuit breaker 10 including an outer case 11 and terminal structures 12 and 13 extending therefrom.
  • the terminal structure 12 is connected within the case by a conductor 14 to a coil 15 forming part of an electromagnet 16.
  • the electromagnet 16 on predetermined overload current conditions, moves axially a tube 2t), which is .partly formed of magnetic material, and functions as an armature for the coil 15.
  • the tube 20 controls a linkage mechanism 21 of the circuit breaker for automatically (on predetermined overload conditions) opening the contacts 22 and 23 by moving the contact 22 out of engage- -ment with the stationary contact v23, the movable contact 22 being carried by a movable contact arm 24 pivoted at the right on laterally projectingkfeet 25.
  • a movable armature (not illustrated) of magnetic material is enclosed by the tube 20 and controls movement downwardly of the tube 20 at certain current conditions by 'itself first -so moving toward the coil 15 to thereafter initiate (after a time delay period) movement of the tube 20, but at higher overload currents movement downwardly of the tube 20 takes place without the need for prior movement of the enclosed movable armature (i.e. instantaneously).
  • Claims to various features relating to the tube 20 are presented in a separate application led January 18, 1963 by Raymond B. Heilman, Serial No. 252,404 and, hence, the tube 20 is not described in detail herein.
  • the coil 15 is formed by a suitable number of turns of wire electrically insulated from each other and wound upon a metal tube of nonmagnetic material.
  • a magnetic frame 27 for the coil 15 is provided by an open ended almost completely annular tube, except for the slot 28 (FIG. 2) through which extends a flexible conductor 29 connected to the movable arm 24.
  • the frame 27 covers and closes the top and extends to the bottom of the coil 15.
  • the bottom of the magnetic frame tube 27 is closed by a magnetic pole piece 31 extending within and just short of the middle of the length of the coil and having a slot (not shown) extending axially similarly to slot 28.
  • VSecured to the pole piece 31 is a bearing 32 through which extends a projection 33 of the tube 20.
  • the mechanism 21 comprises two groups of links referred to for convenience as the handle toggle or first group 41 and the main toggle or second group 42, the two groups being interconnected by an insulator coupler link 43 to transmit forces between the groups during manual and automatic operation.
  • the handle toggle group 41 comprises, in addition to the handle link 35, a link 44 of varying length, hereinafter described in detail.
  • the main toggle group of links 42 comprises upper Vand lower toggle links 48 and 49 (formed by spaced members, FIGS. 4 and 8), controlled by a catch link 50 which is pivotal about fixed pintle 51, the lower toggle link 49 being pivotally connected at its lower end to the movable arm 24 by a pintle 52.
  • the upper toggle link 48 has its upper end pivotally connected by a pintle 53 to one end of the catch link 50 while the adjacent ends of the toggle links 48 and 49 are pivotally connected together by another pintle 54 to form the knee of the main toggle. Overcenter travel of the knee 54 in the closed position of the contacts, FIG. 2, is limited by abutment of the upper extension 56 of link 49 with the iixed lpintle 51.
  • the pintle 51 for the catch link 50 is the only link which is pivoted about a iixed pintle, the other pintles being capable of floating movement, the pintle 51 being supported at its end portions in spaced frame plates 57 and 58.
  • the catch link 50 is controlled by a cradle 61, the upper end of side plate 62 (one of the two side plates forming cradle 61) being in turn restrained (FIG. 10) by the inturned pivotal latch 63 of lock 36.
  • the cradle 61 is biased in a clockwise direction (as viewed in FIG. 2) by a spring 64 (FIGS. 3, 5 and 10) which is coiled about and carried by a pin 65, the spring 64 having one end (the left hand end in FIG. 3) anchored against the frame plate 58 while the other end (the right hand end) underlies and is biased against a pin 66 which is carried by plates 57 and 58 and about which the cradle 61 pivots. Also, clockwise movement of the cradle 61 is limited due to abutment of the edges of the cradle side plates with the coil frame 27, FIG. 1.
  • the latch 63 is pivoted clockwise, FIG. 5, to release the cradle 61, by impingement of the arm 37 (of the counterweight suspension structure 40 secured to the tube 2t) and moved downwardly upon predetermined overload currents) with a trigger arm 70 of the lock 36. Rotation of the latch 63 allows the cradle 61, under pressure from two opening springs '71 connected to the movable arm 24, to rotate counterclockwise until the catch link 50 frees itself from a lock 72 carried by the cradle 61.
  • variable length link 44 in FIG. 1 comprises a ygenerally inverted L-shaped link 75 pivotal about a fixed pintle 76 whose ends are carried by insulator bearing 77 supported by the frame plates 57 and 58, the ends of the pintle 76 extending through an inner case 145 and into contact with the main case part 144 l(as illustrated in FIG. 8).
  • the other end of the L-shaped link 75 is pivotally connected to a floating link 80 and the latter is in turn pivotally connected to the lower end of the handle link 35, the connections being made by a U-shaped member whose legs form pintles 81 and 82, respectively, as illustrated in FIG. 4.
  • a spring 83 which is compressed by a slidable link 84, the latter having shoulder portions 87 (FIG. 8) resting u-pon the upper end of the spring 83, the lower end of the spring 83 resting against the pintle 76.
  • the slidable link 84 also has a lower portion 88 in interfitting, cruciform relationship with the longest part of the L-shaped link 75 (for alignment purposes) and intermediate the pintles 76 and 82.
  • the upper portion of slidable link 84 is split to form V-shapes (FIG. 6) and is seated and biased against the pintle 81 by the spring 83 in all positions of the mechanism.
  • the position of the pintle 82 changes in different positions of the linkage but the pintle 82 is placed relative to the other pintles and the links so that when the handle link 35 is held manually in its contacts closed position (illustrated in FIG. 3), the toggle links 48 and 49 are 'allowed to collapse to fully open the contacts by rotation of the coupler link 43 about pintle 82, which due to the manual force on the handle 34, remains stationary.
  • Movement of the handle link 35, about its tixed pintle 91, is limited by abutment (in the off position of the contacts) of the handle link 35 with the stop pin 92, and (in the contacts closed position) by the stop pin 93.
  • the relative position of the various links and the placement of the pintles of the handle toggle group 41 is such that the pintle 81 defines the knee of a toggle formed by the handle link 35 and the variable length link 44 (i.e. links 75, 80, 84 and spring 83).
  • the spring 83 exerts a force on the pintle 81 tending to move the handle link 35 with a snap action until it abuts with the stops 92 or 93.
  • the handle toggle group of links 41 and four of the live links of the main toggle group of links 42 as forming a four-bar group, but when the mechanism is tripped electromagnetically the tive links of the main toggle group of links 42 becomes a five-bar group. That is, the four bars of the handle toggle group 41 are links 35, 75 and 80 with an imaginary link extending from pintle 76 to pintle 91. During manual opening or closing of the contacts, the four bars of the main toggle group 42 are links 24, 48, 49 (catch link 50 being iixed at this time) with an imaginary link extending from pin 53 to the feet 25 of the movable arm 24.
  • the aforedescribed four-bar group of the main toggle group of links becomes a fivebar group because the catch link 50 now becomes the fourth link of the live-bar mechanism, and an imaginary link now extending from pin 51 to the feet 25 of the movable arm.
  • the lock 36 is statically balanced and pivotally mounted upon a pintle 96 which is staked to frame plate 58 and provided with an enlarged head to hold the lock 36 in proper position.
  • the latch 63 is biased into locking engagement with the cradle 61 by a spring 97 having one end secured to the frame plate 58 and the other end to an arm 98 of the lock 36.
  • the counterweight suspension structure 40 (FIG. 5) is formed by spacd plates 101 and 102 (FIG. 4) which are pivoted intermediate their ends on pintles 103 secured to bendable arms 104, the latter being welded at their right hand ends to the frame plates 57 and 58.
  • the spaced plates 101 and 102 are also pivotally connected by pintles 106 to the tube 20, the pintles 106 being secured to the right of pintles 103 and to the tube 20 by a strap 107 which frictionally and tightly engages the outer surface of the tube 20' and is carried thereby.
  • Springs 108 are provided to bias the pintles 106 above or below the pintles 103, the springs 108 having their right hand ends connected to the counterweight plates 101 and 102 between pintles 104 and 106.
  • the counterweight structure 40 is claimed in a separate patent application led January 18, 1963 by Ronald Nicol, Serial No. 252,413 and therefore is not described in greater detail herein.
  • the movable arm 24 is at all times biased to the open position of the contacts by the two springs 71, the lower ends of which are connected to opposite sides of the movable arm 24 at the pin 52 which also extends beyond the width of the movable arm 24 (FIG. 8) at both ends to engage the frame plates 57 and 58 and thereby limit the travel of the movable arm 24 during the opening of the contacts (FIG. 3).
  • the upper ends of springs 71 are secured to ears 113 carried by a pivotal plate 114, the latter being pivotally supported in bearing notches 115 (FIG. 6) formed in the fra-me plates 57 and 58.
  • the component of the springs 71 trans-mitted by the toggle links 48 and 49 also biases the catch link 50 clockwise against the lock 72.
  • this component of springs 71 decreases in magnitude and exerts a force on the catch link 50 which is less than that of spring 83, whereby the catch link 50 resets due to the force of spring 83.
  • the lock lip 72 is carried in triangular slots 85 and biased upwardly against one edge wall of the slots 85, by the end portions of a U-spring 86, FIG.
  • the latter having coil portions looped about the pin 65 carried by the cradle 61 and the middle or yoke portion biased against the pintle 66 providing the pivotal support for the cradle 61 and the ends of the pintle 66 being supported by the frame plates 57 and 58, the latter being provided with openings 90 to accommodate the rocking movement of the ends of the pin 65 when the cradle 61 moves.
  • the pivotal plate 114 For automatic resetting of the mechanism after removal of a force on the handle 34 tending to keep the contacts closed while an overload persists in the circuit requiring the contacts to open, the pivotal plate 114 carries the leaf reset spring 119 (FIGS. l and 6) disposed in the path of movement of the upper end of the catch link 50 (when Imovement of the handle 34 to the contacts open position is restrained) subsequent to the re- 6 lease of the catch link 50 by the lock 72, for depressing the reset spring 119, using the force obtained from the opening springs 71 after electromagnetic tripping.
  • booster spring 121 Welded to the outer cylindrical magnetic frame 27, positioned so as to be between the side plates of the cradle 61, is a booster spring 121 also for use during automatic resetting after trip free operation.
  • the booster spring 121 (FIGS. l and ll) comprises a flexible leaf 122 extending above the coil frame 27 and in the path of movement of and llexed by the pivotal plate 114 which carries the reset spring 119 and the opening springs 71. Force from the opening springs 71 is stored by the reset spring 119 and the booster spring 121 during movement of the linkage from the position of FIG. 2 toward that of FIG.
  • Pivotal movement of the arm 24, and rolling and sliding movement between the movable contact 22 and the stationary contact 23, is provided by elongated, open-ended slots 125 (FIG. 6), formed in each of the frame plates 57 and 58, which receive the laterally extending feet 25, lthe latter provided at the right ends of the side plates forming the movable arm 24.
  • Coiled about an insulator bearing 126 carried by the frame plates 57 and 58 through which extends a pin 127 (FIGS. 1 and 6) is the Contact force spring 117 having its ends biased against the feet 25 and a yoke portion 129 resting against a pin 130, the pin 130 being peened to the frame plates 57 and 58.
  • Each of the slots 125 is defined by a top arcuate wall 131 and two side walls 132 and 133, the latter two being inclined toward each other to form a V shape, the wall 132 being continued downwardly and vertically as wall 134 to form the lower portion of each slot 125, while the wall 133, however, is continued downwardly as wall 133, but inclined in the opposite direction to the wall 133, to jointly form substantially a point and together with wall 136 the lower open ended portion of each slot 125.
  • initial movement of the movable arm 24 is a sliding movement of the movable contact 22 along the stationary contact 23, because the feet 2S slide to the left (along the walls 136) and upwardly, under the bias of the spring 117, until the upper edges of feet 25 jar or abut with an impact upon the arcuate walls 131. Thereafter, the opening springs 71 continue the opening movement of the arm 24, pivoting the arm 24 at its feet 25 about the point formed by walls 133 and 136.
  • a reset spring 138 for the -tube 20.
  • the spring 138 has one end secured to a plate 139 which is in turn secured to the projection 33 of the tube 20.
  • the other end of the spring 138 is disposed to the left of an extension 140 secured to one of the feet 25.
  • the extension 140 and the associated end of spring 138 are arranged relative to each other so that in the closed position of the contacts, FIG. 2, the extension 140 is spaced from the spring 138 and the spring applies no bias to the tube 2f), at this time.
  • the extension 140 engages the associated end of the spring 138 and depresses it, causing the other end of the spring 138 to exert a force upwardly upon the tube which is suflicient, upon deenergization of the coil 15 (thatis, extinction of any arc that may form) to reset the tube 20 by moving it upwardly sufficiently for the pin i106 of the counterweight structure 40 to move above the center of pin 103, at which time the sus-pension spring 108 also helps to move the tube 20 up to its reset or open position of the contacts.
  • the case 11 comprises a main case part 144 to which is brazed the rim 158 of a bottom terminal block 146.
  • a partial inner case 145 is provided, welded to the bottom terminal block 146 for the purpose of holding the pintles 76 and 127 (and their insulator bearings) in proper alignment during assembly of the unit, the pintles 76 and 127 extending through the inner case 145 and are peened thereto.
  • the plates 57 and 58 are also held in spaced relation with the side walls of the main case part 144 because the ends of pintles 51 and 130 are peened to hold the plates 57 and 58 against shoulders 147 formed by the insulator 'bearing 77 (FIGS. 4 and 8) and similar shoulders formed by the insulator bearing 126.
  • the mechanism is located properly with respect to the case by an insulator 151 (carried by a handle bracket 152 brazed to the case part 144) which receives groove portions 153 of the frame plates 57 and 58.
  • the fixed pintle 91 for the handle link is supported by the bracket 152, the top part of the latter projecting out of the main case part 144 so that the holes for pin 91 are above the top of the case part 144, and a metal bellows 154 is provided to seal the opening 155 in the main case part 144 through which the handle link 35 extends, while at the same time allowing pivotal movement of the handle link.
  • the assembly of the device heretofore described is made by first assembling the aforementioned links and pintles to the frame plates 57 and 58, the magnetic frame 27 of the coil 15 being secured by brackets 156 to the frame plates 57 and 58 (FIG. 7), and the tube 20 being carried in proper position by the counterweight suspension structure 40.
  • the linkage, assembled to the frame plates 57 and 58, together with the coil 15, tube 20, and the terminal block 146 are now inserted into the main case 144 until the handle link 35 extends through the hole 155 in the main case 144 and between the side plates of the handle brack- ⁇ et 152 and until the locating insulator 151 is received in the grooves 153 in the frame plates 57 and 58.
  • the pin 91 is then inserted to secure the handle link 35 to the -handle bracket 152 ⁇ and the opposite walls of the main case 144 are spot welded to the opposite ends of the pintles 76 and 127. Thereafter, the main case 144 is brazed to the rim of the terminal block 146.
  • the handle 34 is crimped to the link 35 and includes a lower inverted dished flange 160 to which is brazed the upper end of the metal bellows 154.
  • the lower end of the bellows 154 is brazed to a dish shaped iiange 161 which is sealed to the main case part 144.
  • the outer met-al case p-arts 144 and 146 are electrically insulated from the electrically conducting parts of the circuit breaker since the terminals 12 and 13 are electrically insulated from the metal supporting structure storming part of the terminal block by being embedded in a ceramic. Claims to various features relating to the terminals 12 and 13 are presented in a separate application filed January 18, 1963 by Raymond B. Heilman Serial No. 252,485 and, hence, they are not described in detail herein.
  • a pair of separable contacts a movable contact ann movable from a contacts closed to a contacts open position, an opening spring for biasing said movable arm to the open contacts position, a rst group of links, a second group of links, a coupler link connecting said two groups of links for transmitting a force from one of said .groups to the other of said groups
  • said first group of links comprising a handle link pivotally connected intermediate its ends to a fixed pintle, a second link of variable length pivotally connected at one end to a fixed pintle and at the other end to a movable pintle for pivotally connecting the variable length link to one end of said handle link, fixed stop pins for limiting pivotal movement of said handle link t0 positions corresponding to the contacts closed and open positions, a spring carried by said variable length link, vsaid spring being connected intermediate the fixed pintle and the movable pintle -for lbiasing said handle link against one or the
  • a pair of separable contacts a movable contact arm movable from a contacts closed to a contacts open position, an opening spring for biasing said movable arm to the open contacts position, a first group of links, a second group of links connected to said movable arm, a coupler link connecting said two groups of links for transmitting a force from one group to the other, said first group of links comprising a handle link and a second link Ipivotally connected to said handle link and forming therewith a rst toggle having a pivotal knee, two stops for limiting overcenter travel of said first toggle to locked positions corresponding to the contacts closed and contacts open positions, a spring connected to the lirst toggle to bias said first toggle against one or the other of its stops when the knee of the first toggle is overcenter, said second group of links including a second toggle having a pivotal knee, said second toggle being formed by a third link one end of which is connected to the movable arm, a fourth link pivot
  • a pair of separable contacts a movable conta-ct arm movable from a contacts closed to a contacts open position, an opening spring for biasing said movable arm to the open contacts position, a first group of links forming a first toggle, a second group of links including a second toggle, a coupler link connecting said toggles, the link of said first toggle to which said coupler link is connected being of varying length, an electromagnetic means for sensing a predetermined overload, said second group of links comprising a catch link controlled by said electromagnetic means for moving one end of said second toggle upon predetermined overload conditions to collapse said second toggle for moving the movable contact arm to the contacts open position, a spring for biasing said first toggle to locked overcenter positions corresponding to the contacts closed and contacts open positions, said second toggle being biased to the locked overcenter position by said opening spring in the contacts closed position independently of the first toggle, whereby the first and second groups of links are independently locked during the closed position of the contacts.
  • first and second toggles each include a pivotal knee
  • said coupler link is :pivotally connected at one end to the varying length link intermediate the ends thereof and at the other end pivotally connected to the knee of the second toggle, whereby upon collapse of the second toggle under pressure of the opening spring in the direction toward said first group of links, said coupler link rotates about its connection to the varying length link until it transmits to the knee of the first toggle a component of the opening spring force at which time it moves the knee of the first toggle overcenter toward its contacts open position and thereafter the spring biasing the first toggle helps complete the movement of the links to the contacts open position.
  • a movable arm carrying said movable contact and having a foot portion eX- tending transverse to the length of the arm, a frame plate having wall structure cooperating with said foot, said wall structure including an arcuate upper wall and a rear wall formed by diverging surfaces defining substantially a pivot point, an opening spring for biasing said arm to the contacts open position and against said rear wall at all times, a contact force spring biasing said foot toward the arcuate upper wall, a linkage mechanism for manually closing and opening said contacts including a toggle connected to said movable arm, electromagnetic means for opening said contacts on predetermined overload currents, manual movement of said linkage meshanism in the direction to close said contacts causing said foot to pivot about said -point and said contacts-to be engaged by each other before said toggle is fully extended, whereby continued movement in the contacts closing direction of said linkage mechanism causes said movable arm to pivot about the stationary contact as a pivot and the movable contact to roll and slide on the .
  • a pair of separable contacts a case enclosing said contacts, a movable contact arm carrying one of said contacts between a contacts closed position and a contacts open position, an opening spring biasing said movable arm to the contacts open position, a first group of links forming an overcenter toggle when said contacts are closed, said first group of links including a handle link to manually move said movable arm between the contacts open and closed positions, a second group of links forming an overcenter toggle when said contacts are closed, a coupler link pivotally connecting said first group of links to said second group of links, and stops limiting overcenter movement of said toggles, said ope-ning spring biasing overcenter the toggle formed by said second group of links, a further spring biasing overcenter the toggle yformed by the first group of links, whereby said groups of links in the contacts closed position form two toggles independently stable of the other and of the coupler link, said second group of links including a catch link, and an electromagnetic means to latch said catch link to resist the
  • a pair of separable contacts a case enclosing said contacts, amovable contact arm carrying one of asid contacts between a contacts closed position and a contacts open position, an opening spring biasing said movable arm to the contacts open position, a first group of links forming an overcenter toggle when said contacts are closed, said first group of links including a handle link to manually move said movable arm between the contacts open and closed positions, a second group of links forming an overcenter toggle when said contacts are closed, a couplerlink pivotally connecting said first group of links to said second group of links, and stops limiting overcenter movement of said toggles, said opening spring biasing overcenter the toggle formed by said second group of links, a further spring biasing overcenter the toggle formed by the first group of links, whereby said groups of links in the contacts closed positions form two toggles independently stable of the other and of the coupler link, said coupler link being pivotally connected to said first and second group of links at locations in which said coupler link is rotatable

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Description

R. B. HEILMAN ETAL v CIRCUIT BREAKER LINKAGE HAVING A TOGGLE March 22, 1966 LINK OF VARIABLE LENGTH 6 Sheets-Sheet l Filed DeC. 24, 1962 INVENTOR RAYMOND BHELMAN BY H Row H March 22. 1966 R. B. HEILMAN ETAL 3,242,286
CIRCUIT BREAKER LINKAGE HAVING A TOGGLE LINK OF VARIABLE LENGTH Filed Deo. 24, 1962 6 Sheets-Sheet 2 It I INVENTOR.
RAYMOND B Hamm BY HARoLo H R.
March 22, 1966 R. B. HEILMAN ETAL 3,242,286
CIRCUIT BREAKER LINKAGE HAVING A TOGGLE LINK OF VARIABLE LENGTH 6 Sheets-Sheet 5 Filed Dec. 24, 1962 \Ol 8\ 8O 57 82 348mg H34 Ob 8 9@ 58 35 40 548 65 5@ '7o lo@ 57 SUSDENsmN STRCTUQE 4o BQOKEM 'www 54 Hana mxo PmrLvom-rfeo Pore Lr-amm ,Mm u
HIHIH m UGS March 22, 1966 R. B. HEILMAN Erm. 3,242,285
CIRCUIT BREAKER LINKAGE HAVING A TOGGLE LINK 0F VARIABLE LENGTH Filed Dec. 24, 1962 6 Sheets-Sheet 4 H5 57 n4 48 9 H5 INVENTOR. RAYMOND B.HE|LMAN BY HAROLD AHR March 22, 12966 R. B. HEILMAN ETAL 3,242,286 CIRCUIT BREAKER LINKAGE HAVING A TOGGLE LINK OF VARIABLE LENGTH 6 Sheets-Sheet 5 Filed Dec. 24, 1962 INVENTOR.
March 22, 1966 R. B HEILMAN Erm.
. CIRCUIT BREAKER LINKAGE HAVING A TOGGLE LINK OF VARIABLE LENGTH 6 Sheets-Sheet 6 Filed DSG. 24, 1962 F O l @E 515m I lo F C.. AD O 4 /N/ m OPENlNGS SPRWGS N S m V @umm MEA o WH W WB n OHM@ w I Mmm Y AA RH w United States Patent v 3,242,286 CIRCUIT BREAKER LIN KAGE HAVING A TOGGLE LINK F VARIABLE LENGTH Raymond B. Heilman, Trenton, NJ., and Harold H.
Bahr, Bronx, N.Y., `assignors to Heinemann lElectric Company, Trenton, NJ., a corporation of New Jersey Filed Dec. 24, 1962, Ser. No. 246,699 Claims. (Cl. 200-106) This invention relates to electric circuit breakers and,
more particularly, to an improved vibration and shock resistant mechanical linkage arrangement for connecting the operating handle to the movable contact arm in a circuit breaker intended to operate between extreme ambien-t temperature limits.
It is an object of -this inevntion to provide a linkage move to the open position when a overload of a predetermined magnitude `persists inthe circuit.
A still further object is to provide a movable contact arm connected to a linkage, the movable contact arm being provided with an improved, simplified arrangement to roll and slide the movable contact (during opening movement of the arm) and abruptly move it so as to break any bond that may have formed between the contacts for facilitating the opening of the contacts.
In one embodiment of this invention a circuit breaker is provided with a pair of separable contacts, one of the contacts being mounted upon a movable contact arm, the latter being pivotal from a contacts closed position to a contacts open position and suitably biased by a spring to the open contacts position. A iirst or handle toggle group of links is provided including a vhandle link connected lto a second link of varying length and together `jointly forming a toggle. A second or main toggle group of links is also provided, the main toggle group of links 4being connected by an insulator coupler link to the handle toggle 4group of links. The main toggle group of links comprises toggle links one of which is connected 'to a catch link and the other to the movable contact arm. The coupler link is connected to the knee of the main toggle and the catch link is controlled by ya rockable cradle and an electromagnetic means. l
Suitable stop means are provided for the handle toggle corresponding to the contacts closed and contacts open positions. The main toggle is provided with means for 'limiting its overcenter travel in the contacts closed position and, further, the movable arm is provided with a stop pin for limiting its movement in the contacts open position.
In the contacts open position, the handle toggle is locked in an overcenter position by a spring carried by the link of varying length which also locks the handle 'toggle in an overcenter position when in the contacts closed position, but on the`other side of the toggle center line. Also, 'in the closed position of the contacts the main toggle links are locked in the overcenter position by the bias of the movable contact opening spring. The coupler link transmits the manual force at the handle (during manual opening and closing) 'to the main toggle, as well a's vtransmitting an initial resetting force from the main toggle to the handle toggle, but when the handle and main toggles are at rest in the closed position of the contacts they are stable independently of each other and of the coupler link which connects them. Therefore, :it
3,242,286 Patented Mar'. 22, 1966 ICC independent, overcenter locked toggles are provided by the links of the mechanism to better resist vibration and shock forces tending to open the contacts of the circuit breaker.
The foregoing and other objects of the invention, the principles of the invention, and the best mode in which it is contemplated applying such principles will more fully appear from the following description and accompanying drawings in illustration thereof.
In the drawings,
FIG. l is a view, partly in section and partly in elevation, of a circuit breaker incorporating this invention with the linkage illustrated in the contacts open position;
FIG. 2 is a view similar to FIG. 1 of the same circuit breaker but illustrating the contacts closed position and taken along the line 2 2 in FIG. 8;
FIG. 3 is a view similar to FIG. 2 but illustrating the position of the linkage when the circuit breaker is tripped electromagnetically and a force is applied to the handle preventing the handle from automatically moving to the contacts open position, that is, the trip free position;
FIG. 4 is a sectional view taken along the line 4 4 in FIG. 3 but part of the suspension structure for the movable tube has been broken away for illustrative purposes;
A FIG. 5 is a partial view ltaken along the line 5 5 in FIG. 4 but in FIG. 5 some of the suspension structure is illustrated which is not illustrated in FIG. 4;
FIG. 6 is a partial, perspective view illustrating part of the linkage in the contacts closed position;
FIG. 7 is a view, partly insection and partly in elevation, for the position of the mechanism illustrated in FIG. 2 with the outer case broken away to better show the relation of the mechanism to the frame plates supporting it;
FIGS. 8, 9, and 10 are sectional views taken along the lines 8 8, 9 9 and 10 10 in FIG. V7;
FIG. 1l is a top view taken along the line 1v1 11 in FIG. l lbut showing the movable tube in elevation; and
FIG. l2 is a diagrammatic view of the linkage after electromagnetic tripping and upon initial movement of the handle toward the contacts open position but prior to com-plete automatic resetting of the mechanism when no force is applied to the handle tending to hold it in the contacts closed position.
Referring to the drawings, there is illustrated a circuit breaker 10 including an outer case 11 and terminal structures 12 and 13 extending therefrom. The terminal structure 12 is connected within the case by a conductor 14 to a coil 15 forming part of an electromagnet 16. The electromagnet 16, on predetermined overload current conditions, moves axially a tube 2t), which is .partly formed of magnetic material, and functions as an armature for the coil 15. The tube 20 controls a linkage mechanism 21 of the circuit breaker for automatically (on predetermined overload conditions) opening the contacts 22 and 23 by moving the contact 22 out of engage- -ment with the stationary contact v23, the movable contact 22 being carried by a movable contact arm 24 pivoted at the right on laterally projectingkfeet 25. A movable armature (not illustrated) of magnetic material is enclosed by the tube 20 and controls movement downwardly of the tube 20 at certain current conditions by 'itself first -so moving toward the coil 15 to thereafter initiate (after a time delay period) movement of the tube 20, but at higher overload currents movement downwardly of the tube 20 takes place without the need for prior movement of the enclosed movable armature (i.e. instantaneously). Claims to various features relating to the tube 20 are presented in a separate application led January 18, 1963 by Raymond B. Heilman, Serial No. 252,404 and, hence, the tube 20 is not described in detail herein.
The coil 15 is formed by a suitable number of turns of wire electrically insulated from each other and wound upon a metal tube of nonmagnetic material. A magnetic frame 27 for the coil 15 is provided by an open ended almost completely annular tube, except for the slot 28 (FIG. 2) through which extends a flexible conductor 29 connected to the movable arm 24. The frame 27 covers and closes the top and extends to the bottom of the coil 15. The bottom of the magnetic frame tube 27 is closed by a magnetic pole piece 31 extending within and just short of the middle of the length of the coil and having a slot (not shown) extending axially similarly to slot 28. VSecured to the pole piece 31 is a bearing 32 through which extends a projection 33 of the tube 20.
Manual opening and closing of the contacts 22 and 23 is initiated yby a handle 34 and a handle link 35, whereas electromagnetic tripping of the contacts to the open position is initiated by pivotal movement of a lock 36 (FIGS. and 7) upon being actuated by a pivotal arm 37 of counterweight suspension structure 40 after suitable axial movement of the tube 20 toward the coil 15.
The mechanism 21 comprises two groups of links referred to for convenience as the handle toggle or first group 41 and the main toggle or second group 42, the two groups being interconnected by an insulator coupler link 43 to transmit forces between the groups during manual and automatic operation. The handle toggle group 41 comprises, in addition to the handle link 35, a link 44 of varying length, hereinafter described in detail.
The main toggle group of links 42, comprises upper Vand lower toggle links 48 and 49 (formed by spaced members, FIGS. 4 and 8), controlled by a catch link 50 which is pivotal about fixed pintle 51, the lower toggle link 49 being pivotally connected at its lower end to the movable arm 24 by a pintle 52. As illustrated in FIG. 2, the upper toggle link 48 has its upper end pivotally connected by a pintle 53 to one end of the catch link 50 while the adjacent ends of the toggle links 48 and 49 are pivotally connected together by another pintle 54 to form the knee of the main toggle. Overcenter travel of the knee 54 in the closed position of the contacts, FIG. 2, is limited by abutment of the upper extension 56 of link 49 with the iixed lpintle 51.. In the main toggle group 42, the pintle 51 for the catch link 50 is the only link which is pivoted about a iixed pintle, the other pintles being capable of floating movement, the pintle 51 being supported at its end portions in spaced frame plates 57 and 58.
The catch link 50 is controlled by a cradle 61, the upper end of side plate 62 (one of the two side plates forming cradle 61) being in turn restrained (FIG. 10) by the inturned pivotal latch 63 of lock 36. The cradle 61 is biased in a clockwise direction (as viewed in FIG. 2) by a spring 64 (FIGS. 3, 5 and 10) which is coiled about and carried by a pin 65, the spring 64 having one end (the left hand end in FIG. 3) anchored against the frame plate 58 while the other end (the right hand end) underlies and is biased against a pin 66 which is carried by plates 57 and 58 and about which the cradle 61 pivots. Also, clockwise movement of the cradle 61 is limited due to abutment of the edges of the cradle side plates with the coil frame 27, FIG. 1.
The latch 63 is pivoted clockwise, FIG. 5, to release the cradle 61, by impingement of the arm 37 (of the counterweight suspension structure 40 secured to the tube 2t) and moved downwardly upon predetermined overload currents) with a trigger arm 70 of the lock 36. Rotation of the latch 63 allows the cradle 61, under pressure from two opening springs '71 connected to the movable arm 24, to rotate counterclockwise until the catch link 50 frees itself from a lock 72 carried by the cradle 61.
Returning to the handle toggle group 41, the variable length link 44 in FIG. 1 comprises a ygenerally inverted L-shaped link 75 pivotal about a fixed pintle 76 whose ends are carried by insulator bearing 77 supported by the frame plates 57 and 58, the ends of the pintle 76 extending through an inner case 145 and into contact with the main case part 144 l(as illustrated in FIG. 8). The other end of the L-shaped link 75 is pivotally connected to a floating link 80 and the latter is in turn pivotally connected to the lower end of the handle link 35, the connections being made by a U-shaped member whose legs form pintles 81 and 82, respectively, as illustrated in FIG. 4. Wrapped around the body portion of the L-shaped link '75 is a spring 83 which is compressed by a slidable link 84, the latter having shoulder portions 87 (FIG. 8) resting u-pon the upper end of the spring 83, the lower end of the spring 83 resting against the pintle 76. The slidable link 84 also has a lower portion 88 in interfitting, cruciform relationship with the longest part of the L-shaped link 75 (for alignment purposes) and intermediate the pintles 76 and 82. The upper portion of slidable link 84 is split to form V-shapes (FIG. 6) and is seated and biased against the pintle 81 by the spring 83 in all positions of the mechanism.
The position of the pintle 82 changes in different positions of the linkage but the pintle 82 is placed relative to the other pintles and the links so that when the handle link 35 is held manually in its contacts closed position (illustrated in FIG. 3), the toggle links 48 and 49 are 'allowed to collapse to fully open the contacts by rotation of the coupler link 43 about pintle 82, which due to the manual force on the handle 34, remains stationary.
Movement of the handle link 35, about its tixed pintle 91, is limited by abutment (in the off position of the contacts) of the handle link 35 with the stop pin 92, and (in the contacts closed position) by the stop pin 93. It will be noted that the relative position of the various links and the placement of the pintles of the handle toggle group 41 is such that the pintle 81 defines the knee of a toggle formed by the handle link 35 and the variable length link 44 (i.e. links 75, 80, 84 and spring 83). Thus, when the pintle 81 is to one side or the other of a center line extending between the pintles 76 and 91, the spring 83 exerts a force on the pintle 81 tending to move the handle link 35 with a snap action until it abuts with the stops 92 or 93.
The characteristic of this mechanism of -high stability to shock and vibration forces is seen by reference to FIG. 2 because the handle group of links 41 is locked in its contacts closed position independent of the main toggle group of links 42 which is also locked in the contacts closed position, i.e., the coupler link 43 could be removed at such time without disturbing the stability of the linkage.
From the foregoing it is seen that in manual movement of the linkage it is possible to View the handle toggle group of links 41 and four of the live links of the main toggle group of links 42 as forming a four-bar group, but when the mechanism is tripped electromagnetically the tive links of the main toggle group of links 42 becomes a five-bar group. That is, the four bars of the handle toggle group 41 are links 35, 75 and 80 with an imaginary link extending from pintle 76 to pintle 91. During manual opening or closing of the contacts, the four bars of the main toggle group 42 are links 24, 48, 49 (catch link 50 being iixed at this time) with an imaginary link extending from pin 53 to the feet 25 of the movable arm 24. Upon electromagnetic tripping and release of the catch link 50, the aforedescribed four-bar group of the main toggle group of links becomes a fivebar group because the catch link 50 now becomes the fourth link of the live-bar mechanism, and an imaginary link now extending from pin 51 to the feet 25 of the movable arm.
The lock 36 is statically balanced and pivotally mounted upon a pintle 96 which is staked to frame plate 58 and provided with an enlarged head to hold the lock 36 in proper position. The latch 63 is biased into locking engagement with the cradle 61 by a spring 97 having one end secured to the frame plate 58 and the other end to an arm 98 of the lock 36.
The counterweight suspension structure 40 (FIG. 5) is formed by spacd plates 101 and 102 (FIG. 4) which are pivoted intermediate their ends on pintles 103 secured to bendable arms 104, the latter being welded at their right hand ends to the frame plates 57 and 58. The spaced plates 101 and 102 are also pivotally connected by pintles 106 to the tube 20, the pintles 106 being secured to the right of pintles 103 and to the tube 20 by a strap 107 which frictionally and tightly engages the outer surface of the tube 20' and is carried thereby. Springs 108 are provided to bias the pintles 106 above or below the pintles 103, the springs 108 having their right hand ends connected to the counterweight plates 101 and 102 between pintles 104 and 106. The counterweight structure 40 is claimed in a separate patent application led January 18, 1963 by Ronald Nicol, Serial No. 252,413 and therefore is not described in greater detail herein.
The movable arm 24 is at all times biased to the open position of the contacts by the two springs 71, the lower ends of which are connected to opposite sides of the movable arm 24 at the pin 52 which also extends beyond the width of the movable arm 24 (FIG. 8) at both ends to engage the frame plates 57 and 58 and thereby limit the travel of the movable arm 24 during the opening of the contacts (FIG. 3). The upper ends of springs 71 are secured to ears 113 carried by a pivotal plate 114, the latter being pivotally supported in bearing notches 115 (FIG. 6) formed in the fra-me plates 57 and 58.
Upon release of the catch link 50, when there is no manual force on handle 34 tending to hold the contacts closed, a sufficient force from the opening springs 71 and a contact force spring 117 (at such time) is transmitted by lower toggle link 49 to the coupler link 43 and the floating link 80 for moving the knee pintle 81 of the handle toggle group 41 to the left (beyond a center link extending between xed4 pintles 76 and 91) at which time the force of spring 83 completes the resetting of the mechanism, such overcenter movement of the pin 81 taking place (at such time) before a reset spring 119 is engaged by the catch link 50. The force of spring 83 rotates the catch link 50 counterclockwise into latching engagement with lock 72. Of course, at all times the cradle 61 and the lock 36 are biased clockwise and counterclockwise respectively, by their springs.
When the contacts are closed, the component of the springs 71 trans-mitted by the toggle links 48 and 49 also biases the catch link 50 clockwise against the lock 72. After the contacts open, however, during automatic resetting, this component of springs 71 decreases in magnitude and exerts a force on the catch link 50 which is less than that of spring 83, whereby the catch link 50 resets due to the force of spring 83. The lock lip 72 is carried in triangular slots 85 and biased upwardly against one edge wall of the slots 85, by the end portions of a U-spring 86, FIG. 5, the latter having coil portions looped about the pin 65 carried by the cradle 61 and the middle or yoke portion biased against the pintle 66 providing the pivotal support for the cradle 61 and the ends of the pintle 66 being supported by the frame plates 57 and 58, the latter being provided with openings 90 to accommodate the rocking movement of the ends of the pin 65 when the cradle 61 moves.
For automatic resetting of the mechanism after removal of a force on the handle 34 tending to keep the contacts closed while an overload persists in the circuit requiring the contacts to open, the pivotal plate 114 carries the leaf reset spring 119 (FIGS. l and 6) disposed in the path of movement of the upper end of the catch link 50 (when Imovement of the handle 34 to the contacts open position is restrained) subsequent to the re- 6 lease of the catch link 50 by the lock 72, for depressing the reset spring 119, using the force obtained from the opening springs 71 after electromagnetic tripping.
Welded to the outer cylindrical magnetic frame 27, positioned so as to be between the side plates of the cradle 61, is a booster spring 121 also for use during automatic resetting after trip free operation. The booster spring 121 (FIGS. l and ll) comprises a flexible leaf 122 extending above the coil frame 27 and in the path of movement of and llexed by the pivotal plate 114 which carries the reset spring 119 and the opening springs 71. Force from the opening springs 71 is stored by the reset spring 119 and the booster spring 121 during movement of the linkage from the position of FIG. 2 toward that of FIG. 3, until the force restraining movement of the handle 34 to the contacts open position is removed or reduced siliciently, at which time, since the coupler link 43 and the upper toggle 48 are in force Atransmitting relation by being in approximately end-to-end relation, the force stored by the reset spring 119 (transmitted through the floating link moves the knee pintle 81 of the handle toggle group 41 from the position illustrated in FIG. 2 to the other side of a center line extending between the pintles 76 and 91, whereupon 4the force of spring 83 also helps complete movement of all the links of the handle toggle group 41 and the main toggle group 42 to the contacts open position.
Pivotal movement of the arm 24, and rolling and sliding movement between the movable contact 22 and the stationary contact 23, is provided by elongated, open-ended slots 125 (FIG. 6), formed in each of the frame plates 57 and 58, which receive the laterally extending feet 25, lthe latter provided at the right ends of the side plates forming the movable arm 24. Coiled about an insulator bearing 126 carried by the frame plates 57 and 58 through which extends a pin 127 (FIGS. 1 and 6) is the Contact force spring 117 having its ends biased against the feet 25 and a yoke portion 129 resting against a pin 130, the pin 130 being peened to the frame plates 57 and 58. Each of the slots 125 is defined by a top arcuate wall 131 and two side walls 132 and 133, the latter two being inclined toward each other to form a V shape, the wall 132 being continued downwardly and vertically as wall 134 to form the lower portion of each slot 125, while the wall 133, however, is continued downwardly as wall 133, but inclined in the opposite direction to the wall 133, to jointly form substantially a point and together with wall 136 the lower open ended portion of each slot 125.
In movement ofthe linkage from the off position (FIG. l) to the on position (FIG. 2 or FIG. 6) the feet 25 pivot about the point junctures of the walls 133 and 136 while Ithe upper edges slide along the arcuate walls 131 until the movable contact 22 abuts the stationary contact 23, the linkage being proportioned so that the contacts abut before the toggle links 48 and 49 go overcenter to the right, at which time continued movement of the handle 34 moves the feet 25 downwardly and to the right along walls 136, about the stationary contact 23 as a fulcrum, the upper edges of feet 25 becoming spaced from the arcuate walls 131 at this time, simultaneously depressing the ends of spring 117.
When the contacts open, initial movement of the movable arm 24 is a sliding movement of the movable contact 22 along the stationary contact 23, because the feet 2S slide to the left (along the walls 136) and upwardly, under the bias of the spring 117, until the upper edges of feet 25 jar or abut with an impact upon the arcuate walls 131. Thereafter, the opening springs 71 continue the opening movement of the arm 24, pivoting the arm 24 at its feet 25 about the point formed by walls 133 and 136.
Coiled about the pin 130 is a reset spring 138 for the -tube 20. The spring 138 has one end secured to a plate 139 which is in turn secured to the projection 33 of the tube 20. The other end of the spring 138 is disposed to the left of an extension 140 secured to one of the feet 25. The extension 140 and the associated end of spring 138 are arranged relative to each other so that in the closed position of the contacts, FIG. 2, the extension 140 is spaced from the spring 138 and the spring applies no bias to the tube 2f), at this time. However, when the mechanism moves from the contacts closed to the contacts open position, whether by manual movement of the handle 34 or electromagnetically by release of the cradle 61 by the lock 36, the extension 140 engages the associated end of the spring 138 and depresses it, causing the other end of the spring 138 to exert a force upwardly upon the tube which is suflicient, upon deenergization of the coil 15 (thatis, extinction of any arc that may form) to reset the tube 20 by moving it upwardly sufficiently for the pin i106 of the counterweight structure 40 to move above the center of pin 103, at which time the sus-pension spring 108 also helps to move the tube 20 up to its reset or open position of the contacts.
, The case 11 comprises a main case part 144 to which is brazed the rim 158 of a bottom terminal block 146. A partial inner case 145 is provided, welded to the bottom terminal block 146 for the purpose of holding the pintles 76 and 127 (and their insulator bearings) in proper alignment during assembly of the unit, the pintles 76 and 127 extending through the inner case 145 and are peened thereto. The plates 57 and 58 are also held in spaced relation with the side walls of the main case part 144 because the ends of pintles 51 and 130 are peened to hold the plates 57 and 58 against shoulders 147 formed by the insulator 'bearing 77 (FIGS. 4 and 8) and similar shoulders formed by the insulator bearing 126. The mechanism is located properly with respect to the case by an insulator 151 (carried by a handle bracket 152 brazed to the case part 144) which receives groove portions 153 of the frame plates 57 and 58. The fixed pintle 91 for the handle link is supported by the bracket 152, the top part of the latter projecting out of the main case part 144 so that the holes for pin 91 are above the top of the case part 144, and a metal bellows 154 is provided to seal the opening 155 in the main case part 144 through which the handle link 35 extends, while at the same time allowing pivotal movement of the handle link.
The assembly of the device heretofore described is made by first assembling the aforementioned links and pintles to the frame plates 57 and 58, the magnetic frame 27 of the coil 15 being secured by brackets 156 to the frame plates 57 and 58 (FIG. 7), and the tube 20 being carried in proper position by the counterweight suspension structure 40. The linkage, assembled to the frame plates 57 and 58, together with the coil 15, tube 20, and the terminal block 146 are now inserted into the main case 144 until the handle link 35 extends through the hole 155 in the main case 144 and between the side plates of the handle brack- `et 152 and until the locating insulator 151 is received in the grooves 153 in the frame plates 57 and 58.
The pin 91 is then inserted to secure the handle link 35 to the -handle bracket 152 `and the opposite walls of the main case 144 are spot welded to the opposite ends of the pintles 76 and 127. Thereafter, the main case 144 is brazed to the rim of the terminal block 146. The handle 34 is crimped to the link 35 and includes a lower inverted dished flange 160 to which is brazed the upper end of the metal bellows 154. The lower end of the bellows 154 is brazed to a dish shaped iiange 161 which is sealed to the main case part 144.
Thus, it is seen that due to the locating insulator 151, the insulator bearings 77 and 126, and the insulator coupler link 43, the outer met-al case p- arts 144 and 146 are electrically insulated from the electrically conducting parts of the circuit breaker since the terminals 12 and 13 are electrically insulated from the metal supporting structure storming part of the terminal block by being embedded in a ceramic. Claims to various features relating to the terminals 12 and 13 are presented in a separate application filed January 18, 1963 by Raymond B. Heilman Serial No. 252,485 and, hence, they are not described in detail herein.
With the mechanism in the contacts open position, as illustrated in FIG. l, manual closing of the contacts is accomplished by manually moving the handle 34 counterclockwise about the pintle 91. This movement of the handle forces the knee pintle 81 to ymove the sliding link 84 down against the upward bias of the spring 83 and further compress the latter, moving the pintle 81 from the position il-lustrated in FIG. 1, on the left of a center line connecting the pintles 76 and 91, toward the right thereof. The L-shaped link carries the pintle 82 about the pintle 76 in a `manner to maintain links 43 and 80 in force transmitting relation .and the L-shaped link 75 performs this same function during electromagnetic tripping. Continued counterclockwise movement of the handle causes the pintle 81 to move through the center line between pintles 76 and 91, to the right hand side thereof, and the line of action of the spring 83 now moves from the left to the right of this line also, the spring 83 now moving the `handle toggle link gro-up to the right, with a snap action, until the handle link 35 abuts against its stop pin 93, FIG. 2, the spring 83 remaining more compressed when the handle link 35 abuts the stop pin 93 than when it abuts stop pin 92.
When the linkage is turned to the closed position of the contacts, FIG. 2, the toggle links 48 and 49 go overcenter to the right and the spring force of the opening springs 71 tend to rotate the catch link 50 clockwise, but rotation of the catch link is restrained by the lock lip 72.
Upon predetermined current conditions the tube 20 moves down sufficiently t0` pivot lock 36 and its latch 63 out of engagement with the cradle side plate 62 at which time the catch link 50 is released by the lock 72. The toggle formed by links 48 and 49 now collapsed to the left and the movable arm 24 moves to its contacts open position under the bias of the opening spring 71 and the contact force spring 117, as illustrated in FIG. ll.
It will thus be seen that when the circuit breaker heretofore described is `associated with other similarly constructed circuit breakers for multipole operation and the handles are mechanically tied together by a tie bar, for instance, the force of the opening springs 71 in the overloaded pole (assuming only one of the multipoles is overloaded sufficiently to require the contacts to open) has to be sufiicient to start not only the handle toggle knee moving past its center line position toward the left but also has to be sufficient to move the handle links of the associated poles sufiiciently to make their handle links group go overcenter also. Of course, after the latter takes place, the spring 83 in the overloaded pole and the associated similar springs in the nonoverloaded poles all help to complete the movement of the mechanisms to the contacts open positions.
Having described this invention, we claim:
1. In a circuit breaker, a pair of separable contacts, a movable contact ann movable from a contacts closed to a contacts open position, an opening spring for biasing said movable arm to the open contacts position, a rst group of links, a second group of links, a coupler link connecting said two groups of links for transmitting a force from one of said .groups to the other of said groups, said first group of links comprising a handle link pivotally connected intermediate its ends to a fixed pintle, a second link of variable length pivotally connected at one end to a fixed pintle and at the other end to a movable pintle for pivotally connecting the variable length link to one end of said handle link, fixed stop pins for limiting pivotal movement of said handle link t0 positions corresponding to the contacts closed and open positions, a spring carried by said variable length link, vsaid spring being connected intermediate the fixed pintle and the movable pintle -for lbiasing said handle link against one or the other of said stop pins when the movable pintleV said fixed pintles, and said second group of links comprising a rst toggle link and a second toggle link jointly forming `a toggle having a pivotal knee to which one end of said coupler link is connected, said first toggle link being pivotally connect-ed to said movable contact arm, manual movement of said handle link .being transmitted by said coupler link to said toggle for manually opening or closing the contacts by movement of said toggle knee toward or away from said first group of links, whereby the opening spring acting on the movable arm causes the movable arm to mo-ve to the open contacts position, a catch link pivotal about another fixed pintle and pivotally connected at one end t said second toggle link, an electromagnet including .an armature for controlling said catch link, whereupon predetermined current conditions and suicient movement of the armature, the Catch link is released, said catch link being 'biased by the opening spring so that upon release of the catch link it pivots and moves one end of the second toggle link to the side of said knee which allows the toggle to collapse under the bias of the opening spring, and a reset spring positioned in the path of movement of one of the links of said second group of links to store energy therein received from the opening spring through the toggle links when movement of said handle link to the contacts open position is restrained during said predetermined current conditions, said reset spring moving said groups of links and the coupler link to the off position after the movable arm Amoves toward its contacts open position and after the restraint is removed from the handle link.
2. In a circuit breaker, a pair of separable contacts, a movable contact arm movable from a contacts closed to a contacts open position, an opening spring for biasing said movable arm to the open contacts position, a first group of links, a second group of links connected to said movable arm, a coupler link connecting said two groups of links for transmitting a force from one group to the other, said first group of links comprising a handle link and a second link Ipivotally connected to said handle link and forming therewith a rst toggle having a pivotal knee, two stops for limiting overcenter travel of said first toggle to locked positions corresponding to the contacts closed and contacts open positions, a spring connected to the lirst toggle to bias said first toggle against one or the other of its stops when the knee of the first toggle is overcenter, said second group of links including a second toggle having a pivotal knee, said second toggle being formed by a third link one end of which is connected to the movable arm, a fourth link pivotally connected to the other end of the third link to form the knee of the second toggle, a further stop for limiting overcenter locking travel of said second toggle when said movable arm is in the contacts closed position, said fourth link being connected to a fifth link, said fifth link being controlled by an electromagnetic means to move the fourth link relative to the knee o f the second toggle for permitting said second toggle to collapse under pressure of the opening spring upon predetermined current conditions, .said opening spring biasing said second toggle against said .further stop when said second toggle is overcenter, whereby the toggles of said first and second groups are independently locked overcenter when said movable arm is in the contacts closed position to minimize accidental movement of the movable contact arm to the contacts open position due to vibration and shock forces upon the circuit breaker.
3. The structure recited in claim 2 wherein said coupler link is formed from insulating material, whereby the first group of links including the handle link is electrically insulated from the electrically energizable portions of the circuit breaker.
4. The structure recited in claim 2 and further including a reset spring in the path of movement of the fourth link, said fourth link and coupler link together forming a l@ force transmitting arrangement, whereby the force of said reset spring moves the knee of the first toggle towards the contacts open position when the movable arm moves to the contacts open position, whereupon the bias of said first mentioned spring completes the movement of all said links to the contacts open position.
5. In an electromagnetic circuit breaker, a pair of separable contacts, a movable conta-ct arm movable from a contacts closed to a contacts open position, an opening spring for biasing said movable arm to the open contacts position, a first group of links forming a first toggle, a second group of links including a second toggle, a coupler link connecting said toggles, the link of said first toggle to which said coupler link is connected being of varying length, an electromagnetic means for sensing a predetermined overload, said second group of links comprising a catch link controlled by said electromagnetic means for moving one end of said second toggle upon predetermined overload conditions to collapse said second toggle for moving the movable contact arm to the contacts open position, a spring for biasing said first toggle to locked overcenter positions corresponding to the contacts closed and contacts open positions, said second toggle being biased to the locked overcenter position by said opening spring in the contacts closed position independently of the first toggle, whereby the first and second groups of links are independently locked during the closed position of the contacts.
6. The structure recited in claim 5 and further including a reset spring means disposed in the path of movement of said catch link subsequent to overload conditions and impingeable by said catch link when said first group of links are restrained from moving during said predetermined overload thereby compressing said reset spring, said coupler link and one of the links of said second toggle being in force transmitting relationship after collapse of said second toggle for moving said first toggle toward the open position of the contacts and moving the catch link to its reset position during opening movement of the links of the second group of links, and a booster spring flexed by said reset spring means to supplement the force of said reset spring means in resetting the links, whereupon on removal of the restraint on said first group of links all of the links are automatically reset.
7. The .structure recited in claim 5 wherein said first and second toggles each include a pivotal knee, said coupler link is :pivotally connected at one end to the varying length link intermediate the ends thereof and at the other end pivotally connected to the knee of the second toggle, whereby upon collapse of the second toggle under pressure of the opening spring in the direction toward said first group of links, said coupler link rotates about its connection to the varying length link until it transmits to the knee of the first toggle a component of the opening spring force at which time it moves the knee of the first toggle overcenter toward its contacts open position and thereafter the spring biasing the first toggle helps complete the movement of the links to the contacts open position.
8. In an electric circuit breaker the combination of stationary and movable contacts, a movable arm carrying said movable contact and having a foot portion eX- tending transverse to the length of the arm, a frame plate having wall structure cooperating with said foot, said wall structure including an arcuate upper wall and a rear wall formed by diverging surfaces defining substantially a pivot point, an opening spring for biasing said arm to the contacts open position and against said rear wall at all times, a contact force spring biasing said foot toward the arcuate upper wall, a linkage mechanism for manually closing and opening said contacts including a toggle connected to said movable arm, electromagnetic means for opening said contacts on predetermined overload currents, manual movement of said linkage meshanism in the direction to close said contacts causing said foot to pivot about said -point and said contacts-to be engaged by each other before said toggle is fully extended, whereby continued movement in the contacts closing direction of said linkage mechanism causes said movable arm to pivot about the stationary contact as a pivot and the movable contact to roll and slide on the .stationary contact and the foot to slide along the `rear wall below said point, said toggle collapsing upon predetermined overload currents, whereby said contact force spring moves said foot against said arcuate upper wall with a sliding movement along said rear wall during which time said movable Contact moves along said stationary contact and said opening springpivots said arm to rotate said movable arm to the contacts open position.
9. .In a circuit breaker, a pair of separable contacts, a case enclosing saidcontacts, a movable contact .arm carrying one of said contacts between a contacts closed position and a contacts open position, an opening spring biasing said movable arm to the contacts open position, a first group of links forming a rst overcenter toggle when said contacts are closed, said first group of links including a handle link to manually move said movable arm between the contacts open and closed positions, a second group of links forming a second overcenter toggle independently stable of said first -overcenter toggle when said contacts are closed, a coupler link pivotally connecting said first group of links to said second group of linksand stops limiting overeen-ter movement of said toggles, said opening springbiasing overcenter the toggle formed by said second group of links, a further spring biasing overcenter to the toggle formed by the first group of links, whereby said groups of links in the contacts closed position form two toggles independently stable of the other and of the coupler link.
10. In a circuit breaker, apair of separable contacts, a case enclosing said contacts, a movable contact arm carrying one of said contacts between a contacts closed position and a contacts open position, an opening spring biasing said movable arm to the contacts open position, a first group of links forming an overcenter toggle when said contacts are closed, said first group of links including a handle link to manually move said movable arm between the contacts open and closed positions, a second group of links forming anovercenter toggle when said contacts are closed, .a coupler link pivotally connecting said first group of links to said second group of 1inks,.and stops limiting overcenter movement of said toggles, said opening spring biasing overcenter the toggle formed by said second group of links, a further spring biasing overcenter the toggle formed by the first group of links, whereby said groups of links in the contacts closed position form two toggles independently stable of the other and of the coupler link, said first group of links including two links which with said last mentioned spring jointly form a link of variable length. v
11. The structure recited4 in claim 9 wherein said .coupler link is lformed of electrical insulation material.
12. In a circuit breaker, a pair of separable contacts, a case enclosing said contacts, a movable contact arm carrying one of said contacts between a contacts closed position and a contacts open position, an opening spring biasing said movable arm to the contacts open position, a first group of links forming an overcenter toggle when said contacts are closed, said first group of links including a handle link to manually move said movable arm between the contacts open and closed positions, a second group of links forming an overcenter toggle when said contacts are closed, a coupler link pivotally connecting said first group of links to said second group of links, and stops limiting overcenter movement of said toggles, said ope-ning spring biasing overcenter the toggle formed by said second group of links, a further spring biasing overcenter the toggle yformed by the first group of links, whereby said groups of links in the contacts closed position form two toggles independently stable of the other and of the coupler link, said second group of links including a catch link, and an electromagnetic means to latch said catch link to resist the tendency of said second group of links t0 collapse under the pressure of the opening spring except on predetermined electrical currents.
13. In a circuit breaker, a pair of separable contacts, a case enclosing said contacts, amovable contact arm carrying one of asid contacts between a contacts closed position and a contacts open position, an opening spring biasing said movable arm to the contacts open position, a first group of links forming an overcenter toggle when said contacts are closed, said first group of links including a handle link to manually move said movable arm between the contacts open and closed positions, a second group of links forming an overcenter toggle when said contacts are closed, a couplerlink pivotally connecting said first group of links to said second group of links, and stops limiting overcenter movement of said toggles, said opening spring biasing overcenter the toggle formed by said second group of links, a further spring biasing overcenter the toggle formed by the first group of links, whereby said groups of links in the contacts closed positions form two toggles independently stable of the other and of the coupler link, said coupler link being pivotally connected to said first and second group of links at locations in which said coupler link is rotatable about its connection to the first group of links during movement of the second group of links to the cotacts open position, even though said handle link is manually restrained from movement.
14. The structure recited in claim 12 and further including a reset spring means disposed in the path of movement of one of the links of said second group subsequent to overload conditions and impingeable thereon when `said first group of links are restrained from moving during predetermined overload, thereby compressing said reset spring.
15. The structure recited in claim 14 and further including a booster spring flexed by said reset spring means to further aid in resetting the links.
References Cited bythe Examiner UNITED STATES PATENTS y 2,833,886 5/1958 Goodwin 200-106 BERNARD A. G1LHEANY,Prr'mary Examiner.

Claims (1)

10. IN A CIRCUIT BREAKER, A PAIR OF SEPARABLE CONTACTS, A CASE ENCLOSING SAID CONTACTS, A MOVABLE CONTACT ARM CARRYING ONE OF SAID CONTACTS BETWEN A CONTACTS CLOSED POSITION AND A CONTACTS OPEN POSITON, AN OPENING SPRING BIASING SAID MOVABLE ARM TO THE CONTACTS OPEN POSITION, A FIRST GROUP OF LINKS FORMING AN OVERCENTER TOGGLE WHEN SAID CONTACTS ARE CLOSED, SAID FIRST GROUP OF LINKS INCLUDING A HANDLE LINK TO MANUALLY MOVE SAID MOVABLE ARM BETWEEN THE CONTACTS OPEN AND CLOSED POSITIONS, A SECOND GROUP OF LINKS FORMING AN OVERCENTER TOGGLE WHEN SAID CONTACTS ARE CLOSED, A COUPLER LINK PIVOTALLY CONNECTING SAID FIRST GROUP OF LINKS TO SAID SECOND GROUP OF LINKS, AND
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3460078A (en) * 1967-09-05 1969-08-05 Texas Instruments Inc Electrical overload circuit breaker
US4051763A (en) * 1964-12-11 1977-10-04 Messerschmitt-Bolkow-Blohm Gesellschaft Mit Beschrankter Haftung Armament system and explosive charge construction therefor
US4882557A (en) * 1987-11-13 1989-11-21 Airpax Corporation Multipole circuit breaker system with differential pole operation
US20110244708A1 (en) * 2008-12-25 2011-10-06 Tatsuya Hayashi Terminal block and method of assembling the same
US8241072B2 (en) 2008-04-25 2012-08-14 3M Innovative Properties Company Push-type connector
EP2947672A1 (en) * 2014-05-23 2015-11-25 Nela, Razvojni Center Za Elektoindustrijo In Elektroniko D.O.O. Protective circuit breaker with toggle trip mechanism

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2833886A (en) * 1954-03-29 1958-05-06 Anatole J Goodwin Air circuit breaker

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2833886A (en) * 1954-03-29 1958-05-06 Anatole J Goodwin Air circuit breaker

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4051763A (en) * 1964-12-11 1977-10-04 Messerschmitt-Bolkow-Blohm Gesellschaft Mit Beschrankter Haftung Armament system and explosive charge construction therefor
US3460078A (en) * 1967-09-05 1969-08-05 Texas Instruments Inc Electrical overload circuit breaker
US4882557A (en) * 1987-11-13 1989-11-21 Airpax Corporation Multipole circuit breaker system with differential pole operation
US8241072B2 (en) 2008-04-25 2012-08-14 3M Innovative Properties Company Push-type connector
US20110244708A1 (en) * 2008-12-25 2011-10-06 Tatsuya Hayashi Terminal block and method of assembling the same
US8210865B2 (en) * 2008-12-25 2012-07-03 3M Innovative Properties Company Terminal block and method of assembling the same
US20120238156A1 (en) * 2008-12-25 2012-09-20 3M Innovative Properties Company Terminal block and method for assembling the same
EP2947672A1 (en) * 2014-05-23 2015-11-25 Nela, Razvojni Center Za Elektoindustrijo In Elektroniko D.O.O. Protective circuit breaker with toggle trip mechanism

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