CA1036645A - Circuit breaker with adjustable thermal trip unit - Google Patents
Circuit breaker with adjustable thermal trip unitInfo
- Publication number
- CA1036645A CA1036645A CA243,696A CA243696A CA1036645A CA 1036645 A CA1036645 A CA 1036645A CA 243696 A CA243696 A CA 243696A CA 1036645 A CA1036645 A CA 1036645A
- Authority
- CA
- Canada
- Prior art keywords
- trip
- circuit breaker
- trip bar
- lever
- movable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
ABSTRACT OF THE DISCLOSURE
A circuit breaker characterized by a stored energy mechanism and an improved resettable latch means which latch means include an adjustable thermal trip unit.
A circuit breaker characterized by a stored energy mechanism and an improved resettable latch means which latch means include an adjustable thermal trip unit.
Description
CROSS-REFERENCE TO RELATED APPLICATION
Cross reference is made to copending applications of E. J Walker, S. No 345,396 now Patent No~ 3,810,051;
- and J. ~O Salvati, S. N. 346,230, now Patent No. 3,797,007 both filed March 29, 1973.
BACKGROUND C~ THE INVENTION
Field of the Invention This invention relates to circuit breakers and, more particularly, to circuit breakers of the type comprlsing an ad~ustable thermal trip unit.
Description of the Prior Art A circuit breaker having an operating mechanism of the type disclosed herein is disclosed in the patent to Albert Ro Cellerini, Patent NoO 3,662,134~ A circuit breaker comprising a stored energy mechanism having a latch structure 20 is disclosed in the patent to Nick Norgian et al, Patent No.
3,460,075. A latch structure of the sub~ect invention con-stitutes a modification over the foregoing prior art in ` that ad~ustable thermal trip means are utilized to change - the rating of thermal elements of all poles with one ad~ust-; ment.
Associated with the foregoing is an arrangement of terminals at the top of the circuit breaker where dead space otherwise exists to enable a reduction in the length of circuit breaker by a dlstance equal to appro~imately twice the 30 width of the terminals.
:. , , A circuit interrupter trip unit comprising a cir-- cuit breaker mechanlsm within a housing and comprising sta-tionary and movable contacts adapted to be connected as part of a distribution unit, a housing comprising opposite pairs of side wallsg end walls, and top and bottom walls, and en-closing a chamber, an arc chute around the path of movement of the movable contact, the circuit breaker mechanism com-prising a releasable member movable when released from a latched position to effect opening of the contacts, a trip ~ bar movable to a trip position to effect release of the .; releasable member and being biased to a latch position, an elongated bimetal movable in response to abnormal currents to effect movement of the trip bar to the unlatched position, ad~ustable means on the trip bar including a threaded screw for increasing and decreasing the amount of the trip bar re-quired for releasing the releasable member, a stationary mag-netic structure for each conductor of the distri~ution sys-~.
.:. tem and comprising a coil and core assembl.y, first conductor means leading from each stationary contact and comprising a : `
first terminal located in the chamber and between the top wall and the arc chute, and second conductor means leading :~ from each movable contact and comprising a second terminal ~ located in the chamber and between the top wall and the .:; . .
stationary magnetic structure.
The advantage of the device of this invention is that it enables a change in the rating of the thermal elements :. with a single adjustment and with the device also provides ~::
for a decrease of the length of the circuit breakerO
Cross reference is made to copending applications of E. J Walker, S. No 345,396 now Patent No~ 3,810,051;
- and J. ~O Salvati, S. N. 346,230, now Patent No. 3,797,007 both filed March 29, 1973.
BACKGROUND C~ THE INVENTION
Field of the Invention This invention relates to circuit breakers and, more particularly, to circuit breakers of the type comprlsing an ad~ustable thermal trip unit.
Description of the Prior Art A circuit breaker having an operating mechanism of the type disclosed herein is disclosed in the patent to Albert Ro Cellerini, Patent NoO 3,662,134~ A circuit breaker comprising a stored energy mechanism having a latch structure 20 is disclosed in the patent to Nick Norgian et al, Patent No.
3,460,075. A latch structure of the sub~ect invention con-stitutes a modification over the foregoing prior art in ` that ad~ustable thermal trip means are utilized to change - the rating of thermal elements of all poles with one ad~ust-; ment.
Associated with the foregoing is an arrangement of terminals at the top of the circuit breaker where dead space otherwise exists to enable a reduction in the length of circuit breaker by a dlstance equal to appro~imately twice the 30 width of the terminals.
:. , , A circuit interrupter trip unit comprising a cir-- cuit breaker mechanlsm within a housing and comprising sta-tionary and movable contacts adapted to be connected as part of a distribution unit, a housing comprising opposite pairs of side wallsg end walls, and top and bottom walls, and en-closing a chamber, an arc chute around the path of movement of the movable contact, the circuit breaker mechanism com-prising a releasable member movable when released from a latched position to effect opening of the contacts, a trip ~ bar movable to a trip position to effect release of the .; releasable member and being biased to a latch position, an elongated bimetal movable in response to abnormal currents to effect movement of the trip bar to the unlatched position, ad~ustable means on the trip bar including a threaded screw for increasing and decreasing the amount of the trip bar re-quired for releasing the releasable member, a stationary mag-netic structure for each conductor of the distri~ution sys-~.
.:. tem and comprising a coil and core assembl.y, first conductor means leading from each stationary contact and comprising a : `
first terminal located in the chamber and between the top wall and the arc chute, and second conductor means leading :~ from each movable contact and comprising a second terminal ~ located in the chamber and between the top wall and the .:; . .
stationary magnetic structure.
The advantage of the device of this invention is that it enables a change in the rating of the thermal elements :. with a single adjustment and with the device also provides ~::
for a decrease of the length of the circuit breakerO
-2-~ .
. , .
., .
', :`, ~: -1~3~6~
BRIEF DESCRIPTION OF THE DRAWING
The single view of the drawing is a vertical ~:
sectional view through one pole of a multipole circuit ~ -! breaker.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing the center pole unit of the three- -. . . -: .
;- pole molded-case or insulating-housing type of circuit breaker is generally indicated at 5. It comprises an insulating housing comprising a molded insulating base 7 including opposite end walls 9 and 11, and a detachable molded insulat-ing cover or top wall 13. Opposite side walls, of which one side wall 14 is shown, are also part of the insulating hous-.
-~ ing. Suitable insulating barriers 15 separate the housing ; -chamber into three ad~acent insulating compartments for housing the three-pole units of the three-pole circuit ` breaker in a manner well known in the art. In each pole unit, two terminals 16 and 17 are provided in proximity to : . :,. .
`~ the opposite end walls 9 and 11 of the housing to enable the .
circuit breaker in an electric distributionO
In each of the three-pole unit compartments of ` the circuit breaker, there are two spaced conductors 19, 21 .; ~
leading to the terminals 16, 17, respectively. A stationary ,-;i .
contact 25 is secured to a conductor 23 which is connected to the conductor 21 by a flexible conductor 27.
~i . A single stored-energy type of operating mechanism ; 29 for controlling all three-pole units is mounted in the ;~ center pole unit of the circuit breakerO The operating ;*
~ mechanism 29 is operable to move a movable contact structure, . .
; generally indicated at 31, between opened and closed posi--~ 30 tions. The movable contact structure 31 is of the type more : ~.
. , .
., .
', :`, ~: -1~3~6~
BRIEF DESCRIPTION OF THE DRAWING
The single view of the drawing is a vertical ~:
sectional view through one pole of a multipole circuit ~ -! breaker.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing the center pole unit of the three- -. . . -: .
;- pole molded-case or insulating-housing type of circuit breaker is generally indicated at 5. It comprises an insulating housing comprising a molded insulating base 7 including opposite end walls 9 and 11, and a detachable molded insulat-ing cover or top wall 13. Opposite side walls, of which one side wall 14 is shown, are also part of the insulating hous-.
-~ ing. Suitable insulating barriers 15 separate the housing ; -chamber into three ad~acent insulating compartments for housing the three-pole units of the three-pole circuit ` breaker in a manner well known in the art. In each pole unit, two terminals 16 and 17 are provided in proximity to : . :,. .
`~ the opposite end walls 9 and 11 of the housing to enable the .
circuit breaker in an electric distributionO
In each of the three-pole unit compartments of ` the circuit breaker, there are two spaced conductors 19, 21 .; ~
leading to the terminals 16, 17, respectively. A stationary ,-;i .
contact 25 is secured to a conductor 23 which is connected to the conductor 21 by a flexible conductor 27.
~i . A single stored-energy type of operating mechanism ; 29 for controlling all three-pole units is mounted in the ;~ center pole unit of the circuit breakerO The operating ;*
~ mechanism 29 is operable to move a movable contact structure, . .
; generally indicated at 31, between opened and closed posi--~ 30 tions. The movable contact structure 31 is of the type more : ~.
-3 . . , . . .. ~ .: . ,:
` 103664S
specifically described in the Cellerini patent 3,662,134. -~
Generally, it comprises a contact arm 33 on which a movable contact 35 is mounted, and a rigid insulating tie bar 37 about which the contact arms 33 rotate. The movable con-tact structure 31 is moved between the opened and closed ~..................................................................... . .
position by the stored energy mechanism 29 which comprises a lower toggle link 39, an upper toggle link 41, a releasable trip member or cradle 43, and tension spring 450 The contact arm 33, for the center pole unit, is pivotally connected to the lower toggle link 39 by a pivot pin 470 The lower link 33 is pivotally connected to the upper toggle link by a knee pivot pin 49. The upper toggle link 41 is pivotally con-nected to the releasable trip member 43 by pivot pin 510 The releasable trip member 43 is supported at one end for pivotal movement above a fixed pin 53 at one end thereo~
and the other end is latched at 55 on a trigger or lever 57 which is pivotally mounted at 59.
An inverted generally U-shaped operating lever 61 is supported at the inner end of the legs thereof for pivotal movement on a pair of fixed pins 63. The tension spring 45 are connected at the lower end to the knee pivot 49 and at the upper end to the bight portion of the operating lever 61. A handle 65 is connected to the upper end of the , . , ~ . ~
operating lever 61 and extends through an opening 67 in a drop .~ wall 13.
. . ;, .
~-' In each pole unit, an arc extinguishing structure : :
.~: or arc chute 69, comprising a plurality of generally U-shaped . magnetic plates 71 is supported in spaced stacked relation-ship. The arc extinguishing structure 69 operates to :
~ - 30 extinguish arcs drawn between the contacts 35, 25 during ; ; - 4 -. .
; -. ,.
:
` lQ366~5 opening operations in a manner well known in the art.
The terminal 17 is located in the chamber between the arc extinguishing structure 69 and the top walls 13 and thereby conserves space and results in a decrease in the overall length of the circuit breaker between the end walls 9 and 11. An openlng 73 is provided in the cover 13 adJ a~
cent to the terminal 17, whereby a cable may be attached to .: .
` I
the terminal, As shown in the drawing, the circuit breaker 5 is `~
~;. 10 in the open positlon with a releasable trip member 43 latched ~:
in the latched pos~tion by means of the trigger or latch lever 57. To close the circuit breaker the handle 65 is ' moved in the clockwise direction from the Y'offt' or open ~ .
; position to the "on" or closed position to move the operating ~ :~i, - - .:
lever 61 clockwise about the pivot 63~ During this movement ~:~ the overcenter springs 45 are moved over center to erect the . .
:' toggle links 39, 41 in order to pivot the movable contact .-: structure 31 of the center pole unit in a clockwise direction . , ~
::~ about the axls of the tie bar 37 to the closed position. The 20 three contact carriers of the circuit breakers are thereby ,, .
. connected for simultaneous movement by the tie bar 37. A
. .:
closed circuit through the circuit breaker 5 extends from ' - the terminal 16 through the conductor 19, a magnetic coil 75, . a conductor 77, a conductor 79, a conductor 81, a flexible ,.~
-- , conductor 83, the conductor arm 33, the contacts 25, 35, and :~ the conductors 23, 27 and 21 to the terminal 17~ To open - ~ the circuit in the circuit breaker the handle 65 is moved ., :-~
.~ counterclockwise to the on position as shown in the drawing~
:; When the circuit breaker is in the closed position :......... 30 and an overload occurs in any of the three-pole units, the `: 5-. ~ _ . . .
. ~ .
, :-.,, `` lQ36645 releasable trip member 43 is released, in a manner here-inafter described, to automatically trip the circuit breaker open. Upon release of a releasable trip arm 43, the springs 45 which are in the charged condition, rotate the releasable trip member 43 in a clockwise direction about the pivot 53 ~-to cause collapse of the toggle 39, 41 to thereby move the three contact carriers 33 to the open position in a manner well known in the artO Upon tripping movement of the circuit breaker, the handle 65 is moved to an inter-mediate position in between the "off" and "on" positions to provide a visual indication that the circuit breaker is tripped open.
Following a tripping operation, it is necessary to reset and relatch the circuit breaker mechanism before the contacts can be closed. Resetting and relatching is achieved by moving the handle 65 to a high position past the "off" positlon. During thls movement a flange 85 is pressed against the upper side of the releasable trip i~member 43 causing it to rotate counterclockwise about the ::' .
~ 20 pin 53, whereby the releasable trip member 43 is moved down . ~
to a position to relatch the trigger or latch lever 57 at 55. ~ollowing relatching of the latch lever 57, when the operator releases the handle 65, the releasable trip i.~ member 43 will again be reset and relatched in the position shown in the drawing. Thereafter the circuit breaker can be operated in the same manner as described above.
In accordance with this invention the circuit breaker comprises a trip bar 87, the trigger or latch lever -57, a bimetal 89, a stationary magnetic structure 91 in- ~ ;
. ,.
`30 cluding the coil 75, and ad~ustable means comprising a latch :
~ 6~
:.
. .. ' . . .... . . . . . .. .. .. . . .
. ,, ,~ ,, . , ., ,, . .` ,. . . .
1(~36645 screw 93O The trip bar 87 is Journally mounted at 95 and is preferably composed of electrically insulating material. .
Moreover, it is coextensive with the three poles of the circuit breaker 5O In each pole the trip bar 87 is pro-vided with a finger 97 which is engaged by a calibration ~:
. screw 99 at the upper end of each bimetal 89. The conductor -79 is composed of a material that is heated in the event of an overload current of a prescribed rating, whereupon the -~
bimetal 89 moves to the right as viewed in the drawing and 10 against the finger 97 D '~ ', .;
Continued movement of the bimetal 89 rotates the .
trip bar 87. The latch screw 93, being mounted on the trip -:` bar 87 by a lateral extension or lever 101, includes a lower .
- end portion 103 which cooperates with the trigger or latch .. :
. lever 57 to retain a releasable trip member 43 in placeO
Upon rotation of the trip bar 87 that latch screw 93 moves upwardly out of engagement with the upper end of the latch ~ lever 57, whereupon the lever rotates counterclockwise ;
` around its pivot 59 and releases the left end of the releas-. 20 able member 43. The distance to which the latch screw 93 must be moved to release the trigger or latch lever 57 is dependent upon the location of the lower end surface 105 of the lower end port~on 103 with respect to the end of the , .~ leverD The latch screw 93 is limited to one full turn by .; means of a mechanical stop 107 on the extension 101 and the screw thread is proportioned to permit an approximate .:; 20% ad~ustment of the nominal thermal rating of the breakerO
. Accordingly, rotation of the latch screw 93 to move the ' : lower end surface 105 up or down with respect to the end ; 30 of the latch lever 57 offers a distance through which the t _7 ' '. ' ~ "
lV3~645 tie bar 87 must move in order to release the releasable trip member 43~
In addition, the tie bar 87 is adapted to be actuated by the stationary magnetic structure 91 by pro-viding an armature lever 1~9 wh~ch is pivoted at 111 and connecting the lever by a link 113 wh~ch extends to the extension 101 on the tie barO When an excessive overload current passes through the coil 75, the armature lever is attracted to a core 115 of the stationary magnetic structure 91, thereby rotating the tie bar 87 counterclockwise and lifting the lower end 105 above the end of the latch lever 57 Accordingly, the circuit breaker of this invention provides a trip unit having an ad~ustable thermal means for changing the rating of the several thermal elements of the three pole units with a single ad~ustment; namely, the match screw 93. Finally, the circuit breaker of this invention has a length which is shorter than that of circuit ....
. breakers of comparable rating due to the placement of the .; 20 terminals in locations within the cover of the breaker ; rather than in locations on opposite side of the stationary magnetic structure and the arc chuteO . :
:-; .
, ;, ~ ..
; , .. ..
,;: , .
.. -. ~.' ~.
., ;~ . ~
', ' '' ' ' ' ~: ' -8- i.
.,~ :
-. :-:
: :
.. :,:
` 103664S
specifically described in the Cellerini patent 3,662,134. -~
Generally, it comprises a contact arm 33 on which a movable contact 35 is mounted, and a rigid insulating tie bar 37 about which the contact arms 33 rotate. The movable con-tact structure 31 is moved between the opened and closed ~..................................................................... . .
position by the stored energy mechanism 29 which comprises a lower toggle link 39, an upper toggle link 41, a releasable trip member or cradle 43, and tension spring 450 The contact arm 33, for the center pole unit, is pivotally connected to the lower toggle link 39 by a pivot pin 470 The lower link 33 is pivotally connected to the upper toggle link by a knee pivot pin 49. The upper toggle link 41 is pivotally con-nected to the releasable trip member 43 by pivot pin 510 The releasable trip member 43 is supported at one end for pivotal movement above a fixed pin 53 at one end thereo~
and the other end is latched at 55 on a trigger or lever 57 which is pivotally mounted at 59.
An inverted generally U-shaped operating lever 61 is supported at the inner end of the legs thereof for pivotal movement on a pair of fixed pins 63. The tension spring 45 are connected at the lower end to the knee pivot 49 and at the upper end to the bight portion of the operating lever 61. A handle 65 is connected to the upper end of the , . , ~ . ~
operating lever 61 and extends through an opening 67 in a drop .~ wall 13.
. . ;, .
~-' In each pole unit, an arc extinguishing structure : :
.~: or arc chute 69, comprising a plurality of generally U-shaped . magnetic plates 71 is supported in spaced stacked relation-ship. The arc extinguishing structure 69 operates to :
~ - 30 extinguish arcs drawn between the contacts 35, 25 during ; ; - 4 -. .
; -. ,.
:
` lQ366~5 opening operations in a manner well known in the art.
The terminal 17 is located in the chamber between the arc extinguishing structure 69 and the top walls 13 and thereby conserves space and results in a decrease in the overall length of the circuit breaker between the end walls 9 and 11. An openlng 73 is provided in the cover 13 adJ a~
cent to the terminal 17, whereby a cable may be attached to .: .
` I
the terminal, As shown in the drawing, the circuit breaker 5 is `~
~;. 10 in the open positlon with a releasable trip member 43 latched ~:
in the latched pos~tion by means of the trigger or latch lever 57. To close the circuit breaker the handle 65 is ' moved in the clockwise direction from the Y'offt' or open ~ .
; position to the "on" or closed position to move the operating ~ :~i, - - .:
lever 61 clockwise about the pivot 63~ During this movement ~:~ the overcenter springs 45 are moved over center to erect the . .
:' toggle links 39, 41 in order to pivot the movable contact .-: structure 31 of the center pole unit in a clockwise direction . , ~
::~ about the axls of the tie bar 37 to the closed position. The 20 three contact carriers of the circuit breakers are thereby ,, .
. connected for simultaneous movement by the tie bar 37. A
. .:
closed circuit through the circuit breaker 5 extends from ' - the terminal 16 through the conductor 19, a magnetic coil 75, . a conductor 77, a conductor 79, a conductor 81, a flexible ,.~
-- , conductor 83, the conductor arm 33, the contacts 25, 35, and :~ the conductors 23, 27 and 21 to the terminal 17~ To open - ~ the circuit in the circuit breaker the handle 65 is moved ., :-~
.~ counterclockwise to the on position as shown in the drawing~
:; When the circuit breaker is in the closed position :......... 30 and an overload occurs in any of the three-pole units, the `: 5-. ~ _ . . .
. ~ .
, :-.,, `` lQ36645 releasable trip member 43 is released, in a manner here-inafter described, to automatically trip the circuit breaker open. Upon release of a releasable trip arm 43, the springs 45 which are in the charged condition, rotate the releasable trip member 43 in a clockwise direction about the pivot 53 ~-to cause collapse of the toggle 39, 41 to thereby move the three contact carriers 33 to the open position in a manner well known in the artO Upon tripping movement of the circuit breaker, the handle 65 is moved to an inter-mediate position in between the "off" and "on" positions to provide a visual indication that the circuit breaker is tripped open.
Following a tripping operation, it is necessary to reset and relatch the circuit breaker mechanism before the contacts can be closed. Resetting and relatching is achieved by moving the handle 65 to a high position past the "off" positlon. During thls movement a flange 85 is pressed against the upper side of the releasable trip i~member 43 causing it to rotate counterclockwise about the ::' .
~ 20 pin 53, whereby the releasable trip member 43 is moved down . ~
to a position to relatch the trigger or latch lever 57 at 55. ~ollowing relatching of the latch lever 57, when the operator releases the handle 65, the releasable trip i.~ member 43 will again be reset and relatched in the position shown in the drawing. Thereafter the circuit breaker can be operated in the same manner as described above.
In accordance with this invention the circuit breaker comprises a trip bar 87, the trigger or latch lever -57, a bimetal 89, a stationary magnetic structure 91 in- ~ ;
. ,.
`30 cluding the coil 75, and ad~ustable means comprising a latch :
~ 6~
:.
. .. ' . . .... . . . . . .. .. .. . . .
. ,, ,~ ,, . , ., ,, . .` ,. . . .
1(~36645 screw 93O The trip bar 87 is Journally mounted at 95 and is preferably composed of electrically insulating material. .
Moreover, it is coextensive with the three poles of the circuit breaker 5O In each pole the trip bar 87 is pro-vided with a finger 97 which is engaged by a calibration ~:
. screw 99 at the upper end of each bimetal 89. The conductor -79 is composed of a material that is heated in the event of an overload current of a prescribed rating, whereupon the -~
bimetal 89 moves to the right as viewed in the drawing and 10 against the finger 97 D '~ ', .;
Continued movement of the bimetal 89 rotates the .
trip bar 87. The latch screw 93, being mounted on the trip -:` bar 87 by a lateral extension or lever 101, includes a lower .
- end portion 103 which cooperates with the trigger or latch .. :
. lever 57 to retain a releasable trip member 43 in placeO
Upon rotation of the trip bar 87 that latch screw 93 moves upwardly out of engagement with the upper end of the latch ~ lever 57, whereupon the lever rotates counterclockwise ;
` around its pivot 59 and releases the left end of the releas-. 20 able member 43. The distance to which the latch screw 93 must be moved to release the trigger or latch lever 57 is dependent upon the location of the lower end surface 105 of the lower end port~on 103 with respect to the end of the , .~ leverD The latch screw 93 is limited to one full turn by .; means of a mechanical stop 107 on the extension 101 and the screw thread is proportioned to permit an approximate .:; 20% ad~ustment of the nominal thermal rating of the breakerO
. Accordingly, rotation of the latch screw 93 to move the ' : lower end surface 105 up or down with respect to the end ; 30 of the latch lever 57 offers a distance through which the t _7 ' '. ' ~ "
lV3~645 tie bar 87 must move in order to release the releasable trip member 43~
In addition, the tie bar 87 is adapted to be actuated by the stationary magnetic structure 91 by pro-viding an armature lever 1~9 wh~ch is pivoted at 111 and connecting the lever by a link 113 wh~ch extends to the extension 101 on the tie barO When an excessive overload current passes through the coil 75, the armature lever is attracted to a core 115 of the stationary magnetic structure 91, thereby rotating the tie bar 87 counterclockwise and lifting the lower end 105 above the end of the latch lever 57 Accordingly, the circuit breaker of this invention provides a trip unit having an ad~ustable thermal means for changing the rating of the several thermal elements of the three pole units with a single ad~ustment; namely, the match screw 93. Finally, the circuit breaker of this invention has a length which is shorter than that of circuit ....
. breakers of comparable rating due to the placement of the .; 20 terminals in locations within the cover of the breaker ; rather than in locations on opposite side of the stationary magnetic structure and the arc chuteO . :
:-; .
, ;, ~ ..
; , .. ..
,;: , .
.. -. ~.' ~.
., ;~ . ~
', ' '' ' ' ' ~: ' -8- i.
.,~ :
-. :-:
: :
.. :,:
Claims (4)
1. A circuit interrupter trip unit comprising a circuit breaker mechanism having separable contacts adapted to be connected as part of a distribution system, the circuit breaker mechanism comprising a releasable member movable when released from a latched position to effect opening of the contacts, a trip bar movable to a tripped position to effect release of the releasable member and being biased in the latched position, a stationary magnetic structure of each conductor of the distribution system and comprising a coil and core assembly and movable in response to excessive overload currents, a lever armature associated with each stationary magnetic structure and operatively connected to the trip bar for moving the trip bar to the unlatched position, an elongated bimetal movable in response to overload currents to effect movement of the trip bar to the unlatched position, and adjustable means on the trip bar for increasing and decreasing the amount of movement of the trip bar required for releasing the releasable member.
2. The trip unit of claim 1 in which the adjust-able means comprises a threaded member.
3. The trip unit of claim 1 in which a trigger lever is operatively mounted between the releasable member and the adjustable means.
4. The trip unit of claim 3 in which the trip bar is rotatable on its longitudinal axis and comprises laterally extending means operatively connected to the lever-armature and the threaded member being mounted on the laterally extending means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA243,696A CA1036645A (en) | 1976-01-16 | 1976-01-16 | Circuit breaker with adjustable thermal trip unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA243,696A CA1036645A (en) | 1976-01-16 | 1976-01-16 | Circuit breaker with adjustable thermal trip unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1036645A true CA1036645A (en) | 1978-08-15 |
Family
ID=4104992
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA243,696A Expired CA1036645A (en) | 1976-01-16 | 1976-01-16 | Circuit breaker with adjustable thermal trip unit |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1036645A (en) |
-
1976
- 1976-01-16 CA CA243,696A patent/CA1036645A/en not_active Expired
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