US3792403A - Circuit breaker - Google Patents

Circuit breaker Download PDF

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Publication number
US3792403A
US3792403A US00147449A US3792403DA US3792403A US 3792403 A US3792403 A US 3792403A US 00147449 A US00147449 A US 00147449A US 3792403D A US3792403D A US 3792403DA US 3792403 A US3792403 A US 3792403A
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United States
Prior art keywords
latch
assembly
housing
contact
circuit breaker
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US00147449A
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English (en)
Inventor
J Bullock
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Cooper Industries LLC
Arrow Hart Inc
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Arrow Hart Inc
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Assigned to COOPER INDUSTRIES, INC, A CORP.OF OHIO reassignment COOPER INDUSTRIES, INC, A CORP.OF OHIO ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: CROUSE-HINDS COMPANY
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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
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/14—Electrothermal mechanisms
    • H01H71/16—Electrothermal mechanisms with bimetal element
    • H01H71/162—Electrothermal mechanisms with bimetal element with compensation for ambient temperature
    • 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
    • H01H73/22—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 electrothermal release and no other automatic release
    • H01H73/30—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 electrothermal release and no other automatic release reset by push-button, pull-knob or slide

Definitions

  • This invention relates to electrical circuit breakers and, more particularly, to a novel circuit breaker incorporating a latch mechanism for holding switch contacts closed and a thermal release mechanism wherein the applied pressure load of the latch mechanism is isolated from the thermal release mechanism and which further includes a temperature compensation means for adjusting the thermal release point of the release mechanism.
  • a circuit breaker of this character includes three principal units, namely, (1) a switch assembly, (2) a latching assembly for moving the switch assembly to the make or closed position and for holding the switch assembly in this position, and (3) a thermal element release assembly for releasing the latch assembly and permitting the switch assembly to return to the break or open position.
  • a switch assembly a switch assembly
  • a latching assembly for moving the switch assembly to the make or closed position and for holding the switch assembly in this position
  • a thermal element release assembly for releasing the latch assembly and permitting the switch assembly to return to the break or open position.
  • the switch assembly includes a pair of stationary terminal contacts secured to the circuit breaker housing and a pair of movable contacts usually secured to a movable block operably connected to the thermal element so as to be responsive to physical displacement of the thermal element to move the movable contacts out of engagement with the stationary contacts.
  • One of the major problems encountered with conventional latch assemblies resides in undesired loading of the release mechanism to maintain the switch mechanism closed. Since opening of the movable contacts of the switch mechanism relies upon movement of the thermal element under load, it is found that contact pressure will be different in similar circuit breaker constructions in a given production run, resulting in inconsistent calibration from one breaker toanother.
  • the bi-metal element is the heart of the circuit breaker and every attempt must be made to allow this element to operate freely and without restriction. If this can be done, a high degree of accuracy and of consistency of response in repeated operations can be achieved to an extent heretofore not attainable in a circuit breaker. Also, since there are many variables in the latch assembly, contact pressure is also adversely affected so that sufficient contact opening clearance cannot be assured repeatedly from one production unit to the next.
  • circuit breakers employ a bi-metal thermal response element which expands in the presence of thermal differentials to release the latch assembly.
  • changes in ambient temperature as well as other environmental conditions sometimes cause the bi-metal element to react in the absence of circuit current overload so that false circuit breaking occurs. Obviously, this is an undesirable event.
  • the present invention provides a latch mechanism having a slidable sleeve adapted to be releasably locked to the housing by a ball whereby the latch load is transferred through the ball and a central shaft assembly to the switch assembly for providing contact pressure.
  • a bi-metal element is coiled about a pair of trip latches in the mechanism that transfers the contact pressure between the latch ball and the switch assembly and which forcibly bear against each other.
  • a selected one of the trip latches is connected to the bi-metal element and is responsive to rotary movement thereof to enable it slide into mating and interleaved relationship with the other trip latch to effect removal of the contact pressure load from the ball.
  • An opening spring forcibly urges the closure contacts of the switch assembly to separate.
  • the selected trip latch is operably coupled to a temperature compensation means carried by the latch mechanism so as to rotate the selected trip latch in response to ambient temperature conditions so that the release of the latch mechanism in response to a circuit overload condition may be more properly determined.
  • Another object of the invention is to provide a temperature compensating means for a circuit breaker adapted to compensate for environmental thermal conditions.
  • Another object of the present invention resides in a novel latch mechanism and release mechanism therefor adapted to open the switch contact in response to a current overload wherein the release mechanism is free from contact pressure loading.
  • Still another object of the present invention is to provide a novel circuit breaker wherein the contact load pressure by-passes the thermal element release mechanism.
  • Another object of the present invention is to provide a novel thermal release assembly for circuit breakers whereby the contact pressure will be the same in' all circuit breakers of similar design of a given production run.
  • FIG. 1 is an elevation view with one half of the housing removed of a novel circuit breaker incorporating the latch and temperature compensation mechanism of the present invention showing the contact closures thereof in their closed position;
  • FIG. 2 is a view similar to FIG. 1 illustrating the latch mechanism released and the contacts in their fully open position;
  • FIG. 3 is an exploded perspective view of major component parts comprising the latch assembly and contact closure mounting assembly;
  • FIG. 4 is an enlarged fragmentary view partly in cross-section of a portion of the latch assembly illustrating the trip cams of latch mechanism in their latched position in;
  • FIG. 5 is a cross-sectional view of the latch members as taken in the direction of arrows 55 of FIG. 4;
  • FIG. 6 is an enlarged elevational view, partly in section, of the contact closure mechanism employed in the circuit breaker of FIGS. 1 and 2;
  • FIG. 7 is an elevational view of inside side of one portion or side of the circuit breaker housing
  • FIG. 8 is an enlarged longitudinal section view of the upper part of the latch assembly illustrated in cocked or loaded condition when the contacts are closed as shown in FIG. 1;
  • FIG. 9 is a view similar to FIG. 8 showing the-latch assembly released such as when the contacts are open as shown in FIG. 2;
  • FIG. 10 is a stepped cross-sectional view of the latch assembly as taken along line 1010 of FIG. 8;
  • FIG. 11 is a top plan view of the temperature compensation means employed in the circuit breaker of FIG. 8 as taken in the direction of arrows 11-11 thereof;
  • FIG. 12 is a longitudinal section view of an electrical circuit breaker incorporating another embodiment of the present invention.
  • FIG. 13 is a view similar to FIG. 12 showing the latch mechanism released and the contacts in their open position;
  • FIG. 14 is an exploded perspective view of the major component parts comprising the latch assembly of FIGS. 12 and 13;
  • FIG. 15 is a transverse section view of the latch assembly of FIGS. 12 and 13 as taken along line 15l5 of FIG. 12;
  • FIG. 16 is an enlarged transverse section view of the contacts mounting assembly shown in FIG. 12 as taken in the direction of arrows 1616 thereof;
  • FIG. 17 is a fragmentary view, in section, of the contact mounting assembly as taken in the direction of arrows l7l7 of FIG. 16;
  • FIG. 18 is an end elevational view of the contact assembly shown in FIG. 16 as taken in the direction of arrows 1818 thereof;
  • FIG. 19 is a transverse sectional view of the temperature compensation means as taken in the direction of arrows along line 19-19 of FIG. 13.
  • FIG. 20 is a transverse section view taken along line 20-20 of FIG. 13.
  • the circuit breaker includes a latch assembly designated generally by numeral 11 and a thermal element release assembly for releasing the latching assembly designated generally by numeral 12.
  • a switch assembly designated generally by numeral 13.
  • the latch assembly, thermal element release assembly and the switch assembly are enclosed within a housing 14.
  • the housing comprises a pair of identical sections which are held together bysuitable fasteners to define an interior cavity in which the components of the circuit breaker are located. As illustrated, only one-half of the housing is shown.
  • the latch assembly 11 is capable of moving the switch assembly to a make or closed position and for holding the switch assembly in this position until released.
  • the latch assembly includes a guide 15 for movably supporting a button 16 which includes an extended portion or sleeve 17 disposed within the interior cavity of the housing.
  • the latch assembly 11 includes a central mounting shaft 18 on which an upper latch member 20 is mounted in nonrotative but axially slidable condition. Shaft 18 is coaxially and coextensively disposed with respect to a lower shaft 21 which carries a lower latch member 22.
  • the latch members are provided with slots defined by spaced apart parallel legs or body portions so that when a mating occurs between alternate slots and legs of the respective latches, the legs will interleave so that loading tension is released from the latch assembly to permit release of the switch assembly.
  • the trip earns 20' and 22 are rotated relative to one another by the thermal element release assembly 12 which includes a coiled bimetal strip 23 having braided wires 24 and 2S welded to the opposite ends thereof and, in turn, having their opposite ends welded to a pair of movable contact arms 26 and 27.
  • the movable contact arms 26 and 27 form a part of the switch assembly and are pivotally mounted at their respective mid-sections to the ends of opposed lateral projections 28 and 29 carried on a vertical slide member 30.
  • the slide member 30 carries shaft 21 and includes a guided body portion which extends downwardly through an insulating washer 31 which is held in a recess in the housing 14.
  • a pair of stationary terminals 32 and 33 which include fixed contacts 34 and 35 residing in the housing interior cavity.
  • the fixed contacts are adapted to be selectively engaged by contact buttons 36 and 37 mounted on movable contact arms 26 and 27.
  • contact pressure ' is mainby means of the forcible urging of spring 40 against flange 41 which bears against the extreme end of the contact arms 26 and 27 so as to pivot the arms in a direction causing the contacts 36 and 37 to press against the fixed contacts 34 and 35 respectively.
  • the upper surface of the opposing ends of the contact arms bear against a pair of semi-circular cams or aligned rounded members 44 carried on the inside surface walls of the housing halves in response to upward movement of the slide member so as to effect fixed and movable contact separation at an exponential rate.
  • the inside surface wall is indicated by numeral 39 in FIG. 7 and semi-circular cam 44 is shown in dotted lines in FIGS. 1 and 2 since it lies behind the mass of slide portion 30.
  • the opposing ends of the contact arms are bifurcated so that the opposite legs loosely embrace the opposite sides of the slide member 30 so as to accommodate its mass therebetween.
  • the push button assembly moves the contact slide assembly 30 down until the movable contact arms 26 and 27 hit the flange 41 on insulating washer 31 whereby the flange exerts pressure against the contact arms as the contacts move downward.
  • the spring 40 then is allowed to transfer its energy into contact pres-v sure.
  • FIG. 3 an exploded view of the central components of the circuit breaker 10 are illustrated so as to show the relative position and location thereof when assembled.
  • the trip cams 20 and 22 which include body portions or legs 45 and 46 respectively.
  • the opposing end of the legs 45 and 46 include opposing surfaces 47 and 48 which abut with one another.
  • the body section 46 upon rotation of trip cam 22 with respect to trip cam 20 in response to movement of the bi-metal element 23, the body section 46 will be forcibly urged into the slots of trip cam 20 between body portions 45. This causes the slide member 30 to move upwardly by the forcible urging of spring 43.
  • the lower shaft 21 seats on a ball or sphere 50 which is supported in a recess 51. I
  • the thermal element release assembly includes the bimetal 23 having its inner end, indicated by numeral 52, secured to an insulating mounting piece 53 via pigtail connector 54.
  • Mounting piece 53 is fixedly secured to the lower trip cam 22 of the latch assembly so that the rotary movement of the bimetal coil is translated into rotational movement of the lower trip latch.
  • thebimetal element 23 is of a type that can absorb 600 in temperature without yielding and shall be of low enough resistance so as not to allow power dissipation to exceed 5 watts. With a rise in bimetal element temperature, an 18 deflection of the coiled element will occur. This high deflection permits consistent calibration.
  • the bimetal element may be helically or coil wound and fixed at one end to the case as indicated by numeral 49.
  • the other end 53 is free to move in a circular motion and is not subjected to latch loading. No load from pushbutton actuation to contact closing passes through the bimetal element. In this manner, the present invention has eliminated the most important factor in inconsistent calibration which is latch loading of the bimetal element.
  • FIG. 4 further shows the trip latches 20 and 22 arranged in end-to-end relationship with the opposing ends of their legs 45 and 46 in forced abutment.
  • the body portions of the trip cam latches will ride into respective slots associated with the other trip cam latch.
  • the trip cam latches 20 and 22 are carried on the shafts segment 18 and 21 respectively.
  • Shaft segment 18 has its end slidably carried within bore 48 formed in the adjacent end of shaft 21.
  • the slide assembly 30 is secured to the lower shaft portion 21 via a connection pin 55.
  • the slide member 30 is in its fully raised or upward position as forcibly urged by spring 43 when the cam latches are interleaved.
  • the contact arms are in their closed or engaged positions with respect to the fixed contacts 34 and 35; however, as shown in broken lines, the contact arms and slide member are elevated so as to provide a substantial clearance between the movable contacts and the fixed contacts.
  • spring 40 urges the upper surface of flange 41 carried on the insulating washer 31 against the yoke end of the contact arm so as to forcibly urge the movable contact into engagement with the fixed contacts.
  • annular bore or opening 56 is provided in the body portion of the slide member 30 to accommodate the spring 43.
  • the spring 43 operates against the base flange of member 41 on one of its ends and against a portion of the slide member terminating the annular space or groove 56 on the slide member.
  • the slide member 30 is further provided with an elongated shank 57 which is slidably inserted into the lower guide 41.
  • FIG. 7 one of the pair of housing halves is illustrated in which the inside wall surface is indicated by numeral 45 for the internal cavity in which rocker or semi-circular surface 44 is disposed.
  • the semi-circular surface 44 is bordered by vertical sections 60 and 61 between which slide member 30 vertically moves.
  • the upward limit of the slide member is restricted by means of engagement with the lower surface of a block 62 disposed between the walls 60 and 61.
  • the bimetal coil is substantially disposed between rounded beads 63 and 64.
  • Housing walls further provide surfaces 65 and 66 on which fixed contacts 34 and 35 may be supported via the terminals 32 and 33. It is to be fully understood that although one-half portion of housing 14 is illustrated in FIG. 7, another identical half portion is employed which cooperates with the internally projecting surfaces and walls such as semicircular portion 44, sections 60 and 61, block 62, and beads 63 and 64, so that the internal cavity may readily house the components previously described and illustrated.
  • guide 15 for button 16 includes a lower annular flange 70 which is held in stationary position between spaced-apart members 71 and 72 of the case.
  • Annular flange 70 is provided with a counterbored shoulder adjacent its central bore entrance which is occupied by a ball race 73 having a central opening therein coaxial with the bore of guide 15.
  • the lower surface of the race 73 adjacent the opening includes a plurality of depressions, such as depression '74, adapted to bear against the periphery of a ball latch 75 when the mechanism is in its latched condition.
  • Pushbutton 16 includes a body portion 76 which is provided with a central bore adapted to receive the end of upper shaft 18.
  • the shaft is connected to the button 16 via a pin 77.
  • button 16 includes a plurality of elongated slots, such as slot 78, as shown more clearly in FIGS. 3 and 10, each of which is adapted to slidably receive a respective ball latch 75 in a vertical direction.
  • sleeve 17 Secured to the pushbutton 16 about its body portion 76 is sleeve 17 which is secured by means of pin 77.
  • button 16, shaft 18, and sleeve 17 form a three part unitary structure adapted to move up and down within the guide 15.
  • annular flange located on one end of sleeve 17 which is adapted to engage with the underside of ball race 73 when the ball latch 75 is in its unlatched condition, as shown in FIG. 9. Also, it is to be noted that the cylindrical body of sleeve 17 is formed with a plurality of longitudinally extending slots, such as open-ended slot 81, which is in corresponding alignment with the slots 78 in the body portion of button 16 and in alignment with the respective indentations 74.
  • a washer 82 Disposed in an annular channel between the outer surface of the cylindrical portion of sleeve 17 and the inner surface of the cylindrical stationary guide 15, there is provided a washer 82 having inwardly pro jected elements 83 that are slidably engaged within the aligned slots 81 and 78 formed in the sleeve and button respectively.
  • Slidable washer 82 is urged against an annular shoulder 84 of the button 16 by means of an expansion latch spring 85 compressed between the washer 82 and the upper surface of ball race 73.
  • the spring 85 is disposed within the channel separating the inside surface of guide 15 with the outside surface of sleeve 17.
  • the normal bias of spring 85 is to forcibly urge the button upwardly into the position shown in FIG. 9 whereby the spring 85 will be fully expanded within its annular channel. Under this condition ball latch will reside within the aligned slots 78 and 81.
  • ball 75 rides on a tapered surface 86 formed on the upper end of trip cam latch 20. This applies a radially outward component of force to the ball 75 forcing the ball into an indentation 74 in the ball race 73.
  • spring 43 forcibly urges or biases the lower shaft 21 upwardly and since the lower trip cam latch 22 is carried thereon, the ends 47 of the latch will be forcibly urged against the ends 48 on the upper trip cam latch 20.
  • the loaded upper trip cam latch 20 is then forcibly urged against one side of the ball latch 75 and the load is transferred through the ball race 73 into the guide 15 and eventually to the housing 14.
  • the latch load transfer into any portion of the thermal release mechanism.
  • Shafts 18 and 21 extend from the pushbutton actuator to the movable contact assembly. Their opposing ends are telescopically related, as shown in FIGS. 4, 8 and 9 so that they are always mated and will always line up coaxially with each other so that the inner shaft 18 will be a guide for the outer shaft 21. Once in position, the shafts will remain assembled and will never be out of position. By employing a release motion which is rotary, a variety of vibration problems are avoided.
  • the outer end of pushbutton 16 is formed with a cavity 88 into which the outer end portion of upper shaft 18 extends. This end is provided with a slot 89 occupied by one end of a temperature compensating bimetal coil 90. The opposite end of the coil is secured to the inside wall surface of pushbutton 16 within cavity 88.
  • the temperature compensating bimetal element 90 may be coiled in a loose condition or a tight condition which will cause a slight rotation of the upper shaft 18 which in turn positions the slot and body portions of the respective trip earns 20 and 22 either nearer or farther apart angularly so that when the main bimetal element 23 moves in a circular direction, the trip camswill trip sooner or later as set by the temperature compensation means.
  • ambient environmental conditions will pre-set or adjust the temperature compensating bimetal element 90 and manual adjustment is not required; however, such adjustment is available.
  • FIG. 12 another embodiment of the present invention is shown in which a single pair of contacts in the switch assembly are provided as well as a simplified latch mechanism.
  • the breaker shown in FIG. 12 is in its closed condition and includes a latch assembly designated generally by numeral 100, a thermal release mechanism designated generally by numeral 101 and a switch assembly designated generally by numeral 102.
  • the present embodiment includes a case or housing 103 having a stationary guide portion 104 closing one end thereof and a base cap 105 closing the opposite end of the housing.
  • a stationarycontact or terminal 106 is fixedly carried on the base cap 105 while an independent second terminal 107 is similarly carried on the base cap.
  • Terminal 106 has a fixed contact surface engageable by a movable contact 108 carried on one end of an arm 110.
  • arm 110 is pivotally mounted on a portion 111 of the housing by means of a pivot 112. Therefore, it can be seen that. contact closure is maintained by the pivoting action of arm 110 so that the contact closure iseither made or broken.
  • the movable contact is normally biased open by a resilient means such as a specially contoured leaf spring 113, or other spring which acts against abase cap portion 114 at one end and against the top surface of the pivotal arm 110 which is at a location normally above the pivot 112.
  • the latch assembly or mechanism 100 which provides the contact pressure includes a pushbutton 115 which is slidably mounted for reciprocal movement within the central bore of the cylindrical portion of guide 104.
  • the pushbutton further includes a central bore in which one end of a central shaft 116 is secured by means of a tangential pin 117 located in a peripheral groove 116g in the center shaft.
  • the center shaft downwardly depends from pushbutton 115 and terminates in sliding relationship within a bore 118 formed in the cap portion 114.
  • a central elongated or elliptical opening 119 accommodates passage of the shaft 116 through the pivotal arm 110 so that no binding or interference exists when either the shaft 116 moves relative to the arm or the arm moves relative to the shaft.
  • a pair of rotating ball bear ings 98 and 99 are carried on the arm so as to reduce friction therebetween as the shaft moves in relation to the arm.
  • the latch mechanism further includes a lower trip latch 120 and an upper trip latch 121 which are carried on the central shaft 116 midway between its opposite ends.
  • Lower trip latch 120 is formed with an elongated, longitudinal groove or channel 122 into which pin 123 is disposed. The axial movement of trip latch 120 with respect to its mounting on the shaft is limited by engagement of pin 123 with the opposite ends of groove or channel 122.
  • the pin 123 is fixedly carried on a circular insulator member 124 which is adapted to rotate approximately 90 during the thermal release action.
  • the lower trip latch 120 includes upwardly projecting parallel legs or body portions 125 and 126 which are in fixed spaced apart relationship and further includes terminating ends 127 which are adapted to press against or abut against ends 128 associated with parallel finger portions 130 downwardly depending from the upper trip latch 121.
  • the respective legs or body portions of the trip latches will interleave in their associated slots when the lower trip latch 120 is rotated with respect to the upper trip latch. Since the lower trip latch is keyed to the member 124 via pin 123, rotation of member 124 will effect rotation of the lower trip latch 120 with respect to the upper trip latch 121 so that the respective legs or body portions will be aligned with associated slots in the opposite trip latch.
  • a sleeve 132 is provided which is fixedly carried by the pushbutton 115 and shaft 116.
  • the sleeve is secured to the pushbutton and shaft via pin 117, so that a three part unitary structure is provided which will move up and down with respect to the housing within guide 104.
  • the upward movement of the unitary structure is restricted by engagement of a flange 133 carried on the end of the sleeve, as shown in FIG. 13, with the underside of a ball race 134.
  • the downward movement of the latch assembly as a structural unit is restricted by engagement of the opposing surfaces 127 and 128 of the trip latches.
  • the ball race 134 includes an indentation 135 which is adapted to receive a part of a ball latch 136 as shown in FIG. 12.
  • the ball When in its latched condition, the ball will not only reside within the indentation 135 but will bear against a tapered surface 137 formed on the upper end of the trip latch 121.
  • the ball latch 136 When the ball latch 136 is in its unlatched condition as shown in FIG. 13, the ball resides within an elongated channel 139 formed in sleeve 132 and partially within a gap 138 formed in the extreme inner end of pushbutton 115.
  • a compressed spring 140 When in its unlatched condition, a compressed spring 140 bears againstthe base cap 105 and against the shaft 116 to forcibly urge the latch assemblyupward within guide 104.
  • the expansive bias of spring 140 is additive to the upward bias of spring 113.
  • the latch assembly 100 is in its locked or latched condition and the applied spring bias of spring 140 is transferred through central shaft 116 and through sleeve 132 and ball latch 136 into race 134 and into the housing. Since the bias of spring 113 normally urges the arm 110 to pivot upwardly, the upper surface of the arm will bear against the lower end of trip latch 120. However, when released, such as by rotating member 124, as will be described later, the lower trip latch 120 will also rotate and align its legs 125 and 126 with the slots or openings defined by the finger portions 130 carried on the upper trip latch 121.
  • the lower latch moves upwardly on the central shaft until the bottom end of the groove 122 abuts the pin 123.
  • the upward movement of the lower latch allows the contact arm 110 to rise to the open position of FIG. 13.
  • the lower trip latch slides through member 124 at this time. Since the upper latch 121 is now unloaded, the trip latch ball 136 will be released and the upward expanding bias of spring 140 will urge sleeve 132 upward to carry the ball into gap 138 and into the condition shown in FIG. 13.
  • the thermal release mechanism 101 includes a helical bimetal element 141 having a plurality of turns disposed coaxially about the shaft 116 within the central cavity of the housing 103.
  • the bimetal element is secured at one end to insulator element 124, as shown in FIG. 20, and is secured at its opposite end to a terminal 142 carried on the housing.
  • Terminal 142 is mechanically and electrically connected to switch terminal 107 via a flexible, braided wire 143.
  • the end of the bimetal element attached to insulator member 124 is in communication with contact 108 via a flexible, braided wire 144. Therefore, the bimetal element 141 is permitted to operate freely and without restriction even when the latch mechanism is loaded.
  • the ball latch 136 moves in and out of gap 138 depending upon whether the ball is in its latched or unlatched condition. As shown in this FIGURE, the ball latch is in its latched condition and gap 135 is not occupied by the ball.
  • FIG. 16 it can be seen that anti-friction balls 98 and 99 are rotatably carried on arm 110 and are disposed on opposite sides of the central shaft 116.
  • FIGS. 16 and 18 show the contact 108 carried on the arm 110 and illustrate the welded connection of one end of braid wire 144 secured thereto.
  • pivot 112 for arm is shown as being connected to the arm via an elongated or elliptical opening 145 which provides a loose connection there'- between so that the exponential separation of the contact closures may be effected by the respective springs as previously described.
  • a temperature compensation means is provided in a fashion similar to that previously described with respect to the embodiment of FIG. 1.
  • the extreme end of central shaft 116 is formed with a slot in order to re ceive and hold one end of a coiled bimetal element 146.
  • the other end of the element as indicated by numeral 147 is secured to the pushbutton 115.
  • the bimetal element 146 resides within an open cavity 148 formed in the pushbutton.
  • the temperature compensation means operates substantially the same as described with respect to the embodiment shown in FIG. 1. The movement of the bimetal coil 146 will cause shaft 116 to rotate accordingly and to align the respective slots and body portions of trip latches and 121 closer or farther apart.
  • circuit breaker embodiments of the present invention provide a novel trip-free latch mechanism and thermal release mechanism that results in advantageous and desirable features not found in the prior art.
  • the release mechanism is not loaded by the latch assembly and is free to operate its release function in a non-restricted condition.
  • the latch mechanism is extremely simple and reliable so that fail-safe techniques and features are embodied therein.
  • the component parts of the circuit breakers may be readily assembled on a mass production basis so that a high yield is obtainable in circuit breaker calibration and repeatability of operation.
  • a housing enclosing a latch assembly; a thermal release assembly including a thermally responsive element for actuating said latch assembly; and a switch assembly including relatively movable contacts operable between closed and open positions, and means to operate said contacts between said positions, said switch assembly being held in its closed position by said latch assembly, and said switch operating means acting independently of said thermally-responsive elment
  • said latch assembly comprising central shaft means carried within said housing, a pair of latch members coaxially mounted on said shaft means and having leg portions engaged in end-to-end relationship in closed circuit position, one of said latch members being mounted on and rotatable about the axis of said shaft means and connected to and operative in response to an electric current overload in said thermal release assembly for rotation relative to said other latch member; the end-to-end engagement of said latch members becoming disengaged after said rotating latch latch member.
  • a circuit breaker as claimed in claim 2 having manually operable means operatingthrough said latch assembly to cause contact engagement, said manually operable means being rendered ineffective upon actuation of said thermal release assembly.
  • thermally responsive means includes a coiled bimetal element positioned coaxially with respect to the aforesaid axis.
  • said switch assembly comprises a slide member coaxially disposed with respect to said latch assembly and said thermal release assembly; a guide member supported by said housing and slidably mounting said slide member for axial movement; a pair of contact arms pivotally mounted on said slide member, each arm having a contact carried on one of its ends; fixed contacts supported by said housing and engageable by said movable contacts; said switch operating means including first resilient means urging said arms in a direction to apply pressure of said movable contacts against said fixed contacts; second resilient means coaxially disposed with respect to said first resilient means and operably coupled between said housing and said slide member urging said slide member in a direction to relieve the contact pressure, to cause pivoting of said arms and contact separation in response to release of said latch assembly.
  • said first resilient means comprises a coiled compression spring engaging the housing and a supporting member slidable relative to said slide member and engaged by said spring and engaging said contact arms.
  • said second resilient means comprises a compressed helical spring coaxial with said first spring.
  • a circuit breaker as claimed in claim 1 having manually operable means operating through said latch assembly to cause contact engagement, said manually operable means being rendered ineffective upon actuation of said thermal release assembly.
  • thermal release assembly includes a helical bimetal element having one end fixedly secured in relation to said housing.
  • said switch assembly comprises a contact arm pivotally mounted on said housing member, said arm having a movable contact carried on its end, a fixed contact sup ported by said housing and engageable by said movable contact, said arm having means engageable by said latch assembly to pivot said movable contact into engagement with said fixed contact, resilient means moving said arm and movable contact into contact disengaged position in response to release of said latch assembly.
  • the invention as claimed in claim 14 including a lost motion pivot connection between said pivotally mounted contact arm and said housing.
  • a housing enclosing a latch assembly, an overload current responsive thermal release assembly for actuating said latch assembly, and a switch assembly including separable contact means held in closed position by said latch assembly
  • said latch assembly comprising first and second elements coaxially disposed in end-to-end abutting relationship, resilient means forcibly urging said elements together, means operably disposed between said first element and said housing to transfer the load of said resilient means to said housing by-passing said thermal release assembly when said elements are in abutment, means operably connecting said second element to said thermal release assembly to disable said abutting relationship on occurrence of an overload permitting said switch assembly to move to open position, and actuating means operating through said transfer means to restore said elements to abutting relationship and said switch assembly to closed position after overload release.
  • said elements comprise a pair of slotted members having body portions in abutment under pressure from said resilient means, and said second element is adapted to align its slots with said body portions of said first element in response to movement of said thermal release assembly enabling the first and second elements to move together.
  • the invention as defined in claim 16 including a temperature compensation means connected to said first element, and means interconnecting said temperature compensating means and said housing.
  • said temperature compensation means comprises a bimetal coil- 20.
  • said invention as defined in claim 16' including central shaft means slidably carrying said first and said secondelements, and wherein said thermal release assembly includes a bimetal coil having one end fixedly connected to said switch assembly and the other end connected to said second abutting element, whereby an overload current said coil moves said second elements with respect to said first element.
  • temperature compensation means including a bimetal coil having one end secured to said shaft, and means interconnecting the other end of said coil and said housing.
  • said transfer means includes means slidably carried on said housing and coaxially disposed with respect to said elements, resilient means yieldably urging said slidable means away from said elements, and ball means engaging with said slidable means and operable to set in a first position between said first element and'said housing to transfer loading from said switch assembly to said housing and operable to move out of said set position when said abutting relationship is disabled.
  • a circuit breaker a housing, a latch assembly enclosed in said housing, a thermal release assembly connected with said latch assembly for releasing it, a switch assembly held in closed position by said latch assembly, said switch assembly comprising a member slidable along an axis, movable contact means operated by movement of said slidable member, fixed contact means supported from said housing and engageable by said movable contact means, said latch assembly comprising relatively movable latch members having endwise abutting portions, means guiding at least one of said latch members for slidable movement coaxially with respect to the other and with respect to said switch-member axis, one of said latch members being turnable about said switch-member axis, a thermally responsive means connected with said turnable latch member and electrically connected with said movable contact means and operated by overload current to cause turning of said turnable latch member permitting relative axial movement of said latch members to cause circuit breaking, said thermally responsive means being independent of the stresses of switch opening and closing forces and also of the forces holding said switch assembly in closed position
  • thermoly responsive means is a coiled bimetal positioned coaxially with respect to the aforesaid axis.
  • a circuit breaker as claimed in claim 23 having means operating through said latch assembly to cause contact engagement, said operating means being rendered ineffective upon actuation of said thermal release assembly.
  • a circuit breaker as claimed in claim 23 having manually operable means operating through said latch members said manually operable means being rendered ineffective on actuation of said thermally responsive means.
  • a circuit breaker a housing, a latch assembly enclosed in said housing, a thermal release assembly connected with said latch assembly for releasing it, a switch assembly held in closed position bysaid latch assembly, said switch assembly comprising a member slidable along an axis, fixed and movable contact means engageable and disengageable by movement of said slidable member, manually operable means movwhen in one axial position being operable by said manual means to move said contact means into engagement, said latch members being relatively rotatable in said one axial position into a position in which one is axially movable relatively to the other to cause disengagement of said contact means; said thermal release assembly comprising means responsive to overload current connected to one of said latch members for moving it rotatively to cause said disengagement, said thermally responsive means being independent of the stresses of switch opening and closing forces and also of the forces holding said switch assembly in closed position.
  • a circuit breaker as claimed in claim 29 in which said overload responsive means is fixedly mounted at one end and movably connected at its other end to one of said latch members and is independent of forces applied by said manual means to close said contact means and of forces tending to separate said contact means.
  • a circuit breaker asclaimed in claim 30 in which said overload responsive means is fixedly mounted at one end and movably connected at its other end to one of said latch members and is independent of forces applied by said manual means to close said contact means and of forces tending to separate said contact means.
  • said latch assembly comprising first and second elements coaxially disposed in end-to-end abutting relationship, resilient means forceably urging said elements together, transfer means including said elements operably disposed between said resilient means and said housing to transfer the load of said resilient means to said housing by-passing said thermal release assembly when said elements are in abutment, means operably connecting said second element to said thermal release assembly to disable said abutting relationship on occurrence of an overload;
  • said switch assembly comprising a fixed contact mounted on said housing, a
  • contact arm having an end pivotally supported from able along said axis to cause engagement of said fixed said housing and a contact on its other end, said switch assembly being engageable with said latch assembly for moving said movable contact into engagement with said fixed contact, said resilient means urging said movable contact away from said fixed contact, and actuating means operating through said transfer means to restore said elements to abutting relationship after overload release.
  • said elements comprise a pair of slotted members having body portions in abutment under pressure from said resilient means, and said second element is adapted to align its slots with said body portions of said first element in response to movement of said thermal release assembly enabling the first and second elements to move together.
  • the invention as defined in claim 33 including a temperature compensation means connected to said first element, and means interconnecting said temperature compensating means and said housing.
  • a housing enclosing a latch assembly; a thermal release assembly including a thermally responsive element for actuating said latch assembly, and a switch assembly including relatively movable contacts operable between closed open positions and means to operate said contacts manually into closed position, said switch assembly being held in its s-ed position by sai latch assembly, and said switch operating means acting independently of said thermall'ywesponsive element, said latch assembly comprising Lgxially movable central shaft means. mounted within said housing,
  • John W. Bullock a pair of latch members coaxially mounted on said shaft means and having; leg portions engaged in end-to-end relationship in closed. circuit position, one on” said latch members being, mounted on and rotatable about the axis of said shaft means and connected to and operative in response to an electric current overload in said thermal release assembly for rotation relative to said other latch member; the end-to-end engagement of said latch members becoming disengaged after said rotating, latch member has rotated through a predetermined angle, thereby permitting separation of said contacts.--; Claim 3, should as follows “3. A circuit breaker as claimed in claim 2 in which said manually operable closing means operates through said latch assembly to cause contact engagement, said manually operable means being rendered ineffective upon actuation of said thermal release assembly.-; Claim 10 should read as follows:
  • a housing enclosing a latch assembly, an overload current responsive thermal release assembly including a thermally responsive element for actuating said latch assembly, and a switch assembly including separable contact means held in closed position by said latch. assembly
  • said latch assembly comprising first and second elements co: exially disposed in end-to-end abutting relationship, resilient Clull I.li*lihl',lE U5! CORR l) ITlQN Patent No. 3,792, O3 Dated February 12 197 Invenwfls) Tohn ⁇ VY Hull oc means forcibly urging 7 said elements together, means operably disposed between.
  • said resilient means to said housing by-passing thermal release assembly when said elements are in abutment, means operably connecting; said second element to said thermally responsive element and to rotate it independently of said contacts and to disable said abutting relationship on occur rence of an overload permitting said switch assembly to move to open position, and actuating means operating through said latch assembly and Dy-passing said thermal release assembly to restore said elements to abutting; relationship and said switch assembly to closed position after overload release.
  • said elements comprise .a pair of slotted members each having body portions positioned on opposite of their said co-axis and adapted to shut in axially balanced condition, said second element being adapted to align its slots with said body portions of said first element in response to movement of said thermal release assembly enabling the first and second elements to move together.--;
  • latch members each have axially extending parallel legs positioned on opposite sides of said axis with recesses therebetween, the ends or said legs abutting in axially balanced condition in one switch position, said legs entering said recesses after predetermined rotation of said turnaole latch member.--;
  • Claim 33, line 13 (Column 16 line 41) 7 insert --one of before “said”; delete "second” before “element”; "element” should be --elements--; Claim 34 should read:
  • said elements comprise a pair of slotted members each having bodv portions positioned on opposite sides of their said co-aXi and adapted to abut in axially balanced condition, said second element being adapted to ali n its slots with said body portions of said first element in response to movement of said thermal. release assembly enabling the first and second elements to move together.

Landscapes

  • Thermally Actuated Switches (AREA)
  • Breakers (AREA)
US00147449A 1971-05-27 1971-05-27 Circuit breaker Expired - Lifetime US3792403A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US14744971A 1971-05-27 1971-05-27

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US3792403A true US3792403A (en) 1974-02-12

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US00147449A Expired - Lifetime US3792403A (en) 1971-05-27 1971-05-27 Circuit breaker

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US (1) US3792403A (fr)
JP (1) JPS5232065B1 (fr)
AU (1) AU448069B2 (fr)
BE (1) BE784096A (fr)
CA (1) CA960263A (fr)
FR (1) FR2139008B1 (fr)
GB (1) GB1383026A (fr)
IT (1) IT958986B (fr)
NL (1) NL7206664A (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4513275A (en) * 1983-03-09 1985-04-23 L'equipement Et La Construction Electrique En Abrege E.C.E. Push-button controlled miniaturized thermal cutout/switch
US6225883B1 (en) * 2000-02-15 2001-05-01 Eaton Corporation Circuit breaker with latch and toggle mechanism operating in perpendicular planes
US6229426B1 (en) * 1999-10-25 2001-05-08 Texas Instruments Incorporated Circuit breaker having selected ambient temperature sensitivity
US20020175786A1 (en) * 2001-04-30 2002-11-28 Wellner Edward Louis Circuit breaker
US6542056B2 (en) 2001-04-30 2003-04-01 Eaton Corporation Circuit breaker having a movable and illuminable arc fault indicator
US6552643B2 (en) * 2000-12-11 2003-04-22 Shang-Hao Chen Structure of a depress-type safety switch
US6639503B2 (en) * 2002-03-07 2003-10-28 Emerson Electric Co. Methods and apparatus for mounting a bimetal coil in a thermostat
US6639492B1 (en) * 2003-01-15 2003-10-28 Eaton Corporation Indicator reset tool, and circuit breaker and method employing the same
US20050275501A1 (en) * 2003-11-14 2005-12-15 Honywell International, Inc. Negative rate switch methods and systems for resilient actuating device
US20060176141A1 (en) * 2005-02-05 2006-08-10 Tsung-Mou Yu Circuit breaker
US20070018772A1 (en) * 2005-07-20 2007-01-25 Tsung-Mou Yu Safety switches
US20090027154A1 (en) * 2007-07-25 2009-01-29 Mills Patrick W Circuit breaker including ambient compensation bimetal holding and releasing arc fault indicator
US20100102658A1 (en) * 2007-01-26 2010-04-29 Vestas Wind Systems A/S High Current Connector

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018172318A1 (fr) 2017-03-20 2018-09-27 Sicpa Holding Sa Matériau stannate de baryum photoluminescent dopé au fer, composition d'encre de sécurité et marque de sécurité en cette dernière

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US2912546A (en) * 1958-05-02 1959-11-10 Texas Instruments Inc Electrical switch structures
US2986620A (en) * 1959-12-29 1961-05-30 Briles Products Inc Circuit breaker

Patent Citations (2)

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Publication number Priority date Publication date Assignee Title
US2912546A (en) * 1958-05-02 1959-11-10 Texas Instruments Inc Electrical switch structures
US2986620A (en) * 1959-12-29 1961-05-30 Briles Products Inc Circuit breaker

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4513275A (en) * 1983-03-09 1985-04-23 L'equipement Et La Construction Electrique En Abrege E.C.E. Push-button controlled miniaturized thermal cutout/switch
US6229426B1 (en) * 1999-10-25 2001-05-08 Texas Instruments Incorporated Circuit breaker having selected ambient temperature sensitivity
US6225883B1 (en) * 2000-02-15 2001-05-01 Eaton Corporation Circuit breaker with latch and toggle mechanism operating in perpendicular planes
US6552643B2 (en) * 2000-12-11 2003-04-22 Shang-Hao Chen Structure of a depress-type safety switch
US6864765B2 (en) * 2001-04-30 2005-03-08 Eaton Corporation Circuit breaker
US6542056B2 (en) 2001-04-30 2003-04-01 Eaton Corporation Circuit breaker having a movable and illuminable arc fault indicator
US20020175786A1 (en) * 2001-04-30 2002-11-28 Wellner Edward Louis Circuit breaker
US6639503B2 (en) * 2002-03-07 2003-10-28 Emerson Electric Co. Methods and apparatus for mounting a bimetal coil in a thermostat
US6639492B1 (en) * 2003-01-15 2003-10-28 Eaton Corporation Indicator reset tool, and circuit breaker and method employing the same
US7378934B2 (en) * 2003-11-14 2008-05-27 Honeywell International Inc. Negative rate switch methods and systems for resilient actuating device
US20050275501A1 (en) * 2003-11-14 2005-12-15 Honywell International, Inc. Negative rate switch methods and systems for resilient actuating device
US20060176141A1 (en) * 2005-02-05 2006-08-10 Tsung-Mou Yu Circuit breaker
US7230516B2 (en) * 2005-02-05 2007-06-12 Tsung-Mou Yu Circuit breaker
US20070018772A1 (en) * 2005-07-20 2007-01-25 Tsung-Mou Yu Safety switches
US7307505B2 (en) * 2005-07-20 2007-12-11 Tsung-Mou Yu Safety switches
US20100102658A1 (en) * 2007-01-26 2010-04-29 Vestas Wind Systems A/S High Current Connector
US8283820B2 (en) * 2007-01-26 2012-10-09 Vestas Wind Systems A/S High current connector
US20090027154A1 (en) * 2007-07-25 2009-01-29 Mills Patrick W Circuit breaker including ambient compensation bimetal holding and releasing arc fault indicator
US7570146B2 (en) 2007-07-25 2009-08-04 Eaton Corporation Circuit breaker including ambient compensation bimetal holding and releasing arc fault indicator

Also Published As

Publication number Publication date
FR2139008B1 (fr) 1979-08-24
CA960263A (en) 1974-12-31
DE2224813A1 (de) 1973-01-04
GB1383026A (en) 1975-02-05
NL7206664A (fr) 1972-11-29
JPS5232065B1 (fr) 1977-08-19
BE784096A (fr) 1972-09-18
DE2224813B2 (de) 1975-11-06
AU4180272A (en) 1973-11-08
FR2139008A1 (fr) 1973-01-05
AU448069B2 (en) 1974-05-09
IT958986B (it) 1973-10-30

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Effective date: 19830223