US3284731A

US3284731A - Auxiliary switch responsive to the movement of the circuit breaker linkage

Info

Publication number: US3284731A
Application number: US315290A
Authority: US
Inventors: Nicol Ronald
Original assignee: Heinemann Electric Co
Current assignee: Heinemann Electric Co
Priority date: 1963-10-10
Filing date: 1963-10-10
Publication date: 1966-11-08
Anticipated expiration: 1983-11-08
Also published as: GB1076447A

Description

Nov. 8, 1966 R. NICOL 3,284,731

AUXILIARY SWITCH RESPONSIVE TO THE MOVEMENT OF THE CIRCUIT BREAKER LINKAGE Filed Oct. 10, 1963 5 Sheets-Sheet 1 H 2% INVENTOR. 28 6? 7 I] j Nov. 8, 1966 R. NICOL 3,284,731

AUXILIARY SWITCH RESPONSIVE TO THE MOVEMENT OF THE CIRCUIT BREAKER LINKAGE Filed Oct. 10, 1963 5 Sheets-Sheet :5

PO/V/M .0 /V/ C 01 BY T Mi 5 I 4727 M5 A77%X5 United States Patent AUXILIARY SWITCH RESPONSIVE TO THE MOVE- MENT OF THE CIRCUIT BREAKER LINKAGE Ronald Nicol, Trenton, N.J., assignor to Heinemann Electric Company, Trenton, N.J., a corporation of New Jersey Filed Oct. 10, 1963, Ser. No. 315,290 6 Claims. (Cl. 33521) This invention relates to electric switches and more particularly to a switch in combination with a circuit breaker. It is an object of this invention to provide an improved switch and an improved switch in combination with a circuit breaker.

Alarm or auxiliary switches have been used in conjunction with circuit breakers for many years to indicate at a remote location whether the circuit breaker is in the contacts closed or open position. In order to indicate this, the alarm switch has been positioned to be actuated directly by the movable contact arm of the circuit breaker, so that whether the circuit breaker contacts are opened manually or whether the contacts are opened electrically, such as on predetermined overload conditions in the circuit breaker, the alarm switch will be actuated to indicate at a remote location that the circuit breaker contacts are open.

As is known, the contacts of the circuit breakers may wear away during the life of a circuit breaker. Thus, the circuit breaker movable arm is frequently constructed to take into account this contact wear. It is a further object of this invention to provide an alarm switch positioned relative to the movable contact arm so that any circuit breaker contact wear which may take place during the life of the circuit breaker will not affect the reliability and operation of the alarm switch.

In the preferred form of the improved alarm switch three terminals are provided. Two of these terminals are positioned so that they define spaced contact portions one of which overlies the other and between these contact portions is positioned a movable contact blade. The movable contact blade is pivotally seated at one end and biased by a spring toward one of the terminal contact portions, but movable away therefrom and into engagement with the other terminal contact portion, by an actuator or finger engageable with a portion of the circuit breaker movable arm.

The circuit breaker is of the type having a linkage comprising a movable arm connected intermediate its end portions by a pin to an overcenter toggle mechanism. At one end the circuit breaker movable arm is provided with a contact and at the other end with an elongated slot through which extends a second pin carried by spaced frame plates, the pin being at one end of the slot when the contacts are open. When the handle of the circuit breaker is moved to the closed contacts position, the overcenter toggle mechanism moves the movable arm toward the stationary contact, the movable contact normally engaging the stationary contact before the toggle mechanism completes its movement at which time continued closing movement of the handle pivots the movable arm about the stationary contact, further stressing an opening spring which engages the movable arm between the first and second pins, and moves the slotted end of the movable arm relative to the second pin so that the latter is intermediate the ends of the slot when the contacts are closed, but it is seen that movement of the slotted end of the movable arm at such time will vary as the contacts wear.

is positioned relative to the movable arm so as to engage the latter along the path of movement of the movable "ice arm directly opposite the pin connecting the movable arm to the toggle mechanism. Since the length of the toggle mechanism remains constant, the toggle mechanism moves the pin connecting it to the movable arm to virtually the same place during closing movement of the circuit breaker contacts, even though the contacts may have worn. Hence, the alarm switch movement during closing of the circuit breaker contacts will be independent of the circuit breaker contact wear.

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. 1 is a perspective view of a two pole circuit breaker embodying this invention;

FIG. 2 is a side elevation, partly in vertical section, with one of the frame plates removed illustrating the circuit breaker contacts of one pole in the closed position;

FIG. 3 is an enlarged side elevation, partly in vertical section, of the lower portion of the circuit breaker pole illustrated in FIG. 2, but its contacts are here illustrated in the open position, and the normally closed alarm switch contacts being engaged;

FIG. 4 is a view similar to FIG. 3, but the circuit breaker pole is shown 'with its contacts closed and the normally open alarm switch engaged;

FIG. 5 is a top view taken along the line 55 in FIG. 3; and

FIG. 6 is a side view taken along the line 6-6 in FIG. 4.

Referring to the drawings, FIG. 1 illustrates a two pole circuit breaker unit to one pole of which has been added an alarm switch 12. The circuit breaker unit comprises a metallic case 13 enclosing the two similarly constructed circuit breaker poles and hereinafter only the parts of the circuit breaker pole associated with the alarm switch 12 will be described for brevity.

As illustrated, the circuit breaker comprises a stationary contact 16, connected to a terminal 28, and a movable contact 17 enclosed by the case 13. The actuation of the movable contact 17 is fully set forth in Patents Nos. 2,360,922 and 3,098,910, but for claritys sake may be described as follows: The movable contact 17 is carried at one end of a movable arm 18 which is biased by a spring 20 toward the open position of the

contacts

16 and 17. The movable arm 18 is connected by a pin 22 to a latching toggle mechanism 24 which is in turn connected to a master handle 26. When the handle 26 is rotated to its clockwise position, the position illustrated in FIG. 2, the latching mechanism 24 and the movable arm 18 all move down to bring the movable contact 17 into engagement with the stationary contact 16 against the bias of the spring 20, the

contacts

16 and 17 assuming the position illustrated in FIGS. 2 and 4. Upon the occurrence of an overload condition, an armature 30 is magnetically attracted toward the pole 32 at one end of the solenoid coil 34, the latter being connected by a conductor to the terminal 29 and by a flexible conductor to the movable arm 18.

The movement of the armature 30 toward the pole 32 causes the oppositely extending unlatching member 36 to move to the left and trip the arm 38 which is secured to a half-moon shaped pintle 40 that is spring biased into latching engagement with the tooth 41 of the catch link 42, the latter forming part of the toggle mechanism 24, so that upon suflicient movement of the arm 38 and the half-moon pintle 4%), the tooth 41 is released and the toggle mechanism 24 collapses under pressure of the spring 20, the movable arm 18 and the toggle mechanism 24 moving up and the handle 26 rotating counterclockwise to the contacts open position partially illustrated in FIG. 3. When the

contacts

16 and 17 are engaged, the arm 38 is located immediately to the left of the unlatching member 36, as illustrated in FIGS. 2 and 4.

The tripping of an adjacent pole is affected upon the automatic tripping of any one pole through the pivotal trip lever 46 and the common insulator bar 47 which connects the trip levers 46 of adjacent poles. Each trip lever 46 is formed with a portion 48 in the path of movement of the toggle mechanism 24 during its collapsing movement and another portion 49 engageable with the armature 30. Rotation of the trip lever in one pole thus causes the rotation of the armature of the adjacent pole,

moving the armature in the direction to release its associated toggle mechanism, thereby opening the contacts of all the poles upon an overload in any one pole.

The metallic case 13 includes a bottom 60 to which the alarm switch 12 is secured, the alarm

switch comprising terminals

61, 62 and 63 which extend through an insulator 65, preferably a high dielectric material such as glass, bonded to a metal ring 66, the latter being soldered at its periphery to the edge portions of a hole in the bottom 60.

The

terminals

61 and 62 have

upper contact portions

67 and 68 disposed within the circuit breaker case, spaced from each other, and bent at a right angle to the major portion of the terminals and'overlying each other in crossed relation, as illustrated in FIG. 5.

The terminal 63 includes an upper support portion 69, generally bent into the shape of an inverted Z having a .lower arm 70 extending in one direction and an upper arm 71 extending in the opposite direction connected by a body portion 72. The

terminals

61, 62 and 63 comprise shaft portions the major extent of which are brazed to supporting, covering sleeves 58 of a suitable alloy to facilitate bonding to the insulator 65 and the lower portions of the terminals are flattened and provided with holes to receive suitable conductors. The lower arm 70 has a hole through which the shaft portion of the terminal 63 extends and is suitably secured thereto.

A movable contact blade 77 of Y shape in form is disposed with its root 78 between the

terminal contact portions

67 and 68, so that raised and depending

contacts

77a and 77b are engageable therewith, and is provided with a hole in which is received one end of a spring 85, the other end of the spring 85 being received in a notch formed in the arm 71, FIG. 5.

The body portion 72 has at opposite edge portions two

notches

87 and 88, FIGS. and 6, the extremities of the

legs

80 and 81 forming L-shaped shoulders inverted with respect to one another and defining tongues which are received in the

notches

87 and 88, the remaining portion of the shoulders pivotally abutting against the body portion 72. The spring 85 biases the contact blade 77 toward the body portion 72 at all times and the interfitting relationship between the shoulders of

legs

80 and 81 and the

notches

87 and 88 restrains lateral movement of the contact blade relative to the support 69 and also provides a pivotal connection between the movable blade 77 and the stationary body portion 72. Further, the body portion 72 and its upper arm 71 are cut out so as to accommodate a part of the spring 85, and, as illustrated in the drawings, the space formed between the two

legs

80 and 81 also accommodating a part of the spring 85 to achieve a compact arrangement.

The left hand portion of the root 78 is formed with an upstanding projection 90 extending toward the movable arm 18 and rigidly secured to the upstanding projection 90 is an elongated actuator, plunger or finger 92 of electrical insulating material, such as nylon, engageable by a movable arm portion or surface 120.

The pin 110 about which the movable arm 18 pivots has end portions carried by two spaced frame plates 100, one only illustrated in FIGS. 3 and 4, and the movable arm 18 moves intermediate these frame plates.

plates, the link 114 being connected, near its bottom end,

to the upper end of the catch link 42 of the toggle mechanism 24, the latter being also movable intermediate the frame plates 100.

The various parts are proportioned so that the pin is at the lower end of the slot 111 when the

contacts

16 and 17 are open. When the handle of the circuit breaker is moved toward the closed contacts position the toggle mechanism 24 moves the movable arm 18 toward the stationary contact 16, the movable contact 17 normally engaging the stationary contact 16 before the toggle mechanism 24 completes its movement at which time continued closing movement of the handle pivots the movable arm 18 about the stationary contact 16, further stressing the opening spring 20' and moving the slotted end of the movable arm 18 relative to the pin 110 until the pin 110 is intermediate the ends of the slot 111, when the

contacts

16 and 17 are closed. It is thus seen that as the

circuit breaker contacts

16 and 17 wear down or the plane of abutment between the

contacts

16 and 17 changes for any reason, the position of the pin 110 in the slot 111 will also change but the position to which the pin 22 moves during closing of the contacts remains the same.

The surface 120, which is engageable with the actuator 92, is the part of the movable arm 18 directly below the pin 22, when the movable arm is in the circuit breaker contacts closed position, and the surface extends sufficiently to both sides to insure engagement with the actuator 912. Hence, the positions of the surface 120 during closing and opening movements of the movable arm 18 are always substantially the same whether or not the

contacts

16 and 17 wear.

The alarm switch 12 is positioned relative to the pin 22 (connecting the movable arm 18 to the toggle mechanism 24) and the various parts are so proportioned so that when the actuator 92 engages the surface 120, (during movement of the arm 18 toward the contacts closed position), the raised contact 77a separates from the upper contact 68 and moves down until the depending contact 77b engages the lower contact 67, the contact blade 77 being slightly flexed at this time under pressure of the surface 120. Of course, during opening movement of the

circuit breaker contacts

16 and 17 disengagement takes place between the surface 120 and actuator 92, allowing the spring to pivot upwardly the blade 77 until the contact 77a engages the upper contact 68.

As illustrated, an inner case 129 of insulation material is provided having a bottom wall 130 defining a circular hole 131 through which the circuit breaker terminal 28 extends and an elongated hole 133 for the other circuit breaker terminal 29. The bottom Wall 130 also defines a further circular hole 136 into which the upper portions of the

terminals

61, 62 and 63 extend. An insulator sheet 140 extends over the bottom wall 130 and closes off most of the tops of the

holes

133 and 136, but the small part of the hole 136 through which the actuator 92 extends is uncovered, the actuator 92 being suitably spaced in all positions from the wall defining the hole 136 and the left edge (FIG. 3) of the insulator sheet 140. The sheet 140 is sufliciently flexible to bend over the ears 112 and extend between the frame plates 100. Further, the sheet 140 extends upwardly at a right angle to further electrically insulate the coil 34 from the conductor which connects the coil to the terminal 29.

Therefore, it is seen that the actuator of the alarm switch always engages the movable arm at substantially the same place even though the circuit breaker contacts may wear, because the actuator is positioned relative to the circuit breaker movable arm so as to engage the latter along the path of movement of the movable arm directly opposite the pin connecting the movable arm to the toggle mechanism. Hence, movement of the alarm switch contact blade is independent of the circuit breaker contact wear.

While the invention has been illustrated and described in combination with a two pole circuit breaker it is understood that the invention is equally applicable to a single pole circuit breaker or to a circuit breaker having more than two poles.

Having described this invention, I claim:

1. An auxiliary switch for a circuit breaker comprising three terminals, two of said terminals having spaced contact portions one of which overlies the other, said third terminal being spaced from said two terminals, a movable contact blade having a first end portion on a support portion of said third terminal and a middle portion disposed between the terminal contact portions, a spring biasing said blade towards one of the terminal contact portions and against said support portion at all times, said spring being connected at one end to said blade and at the other end to said third terminal portion, said blade being movable between said terminal contact portions against said spring bias to alternately contact one or the other of said terminal portions, said movable contact blade being resilient, a second end of said movable contact blade having an insulator secured thereto to elastically deform said movable contact blade and thereby insure contact between said movable contact blade and one of said terminals as a result of such deformation, the end of said movable contact blade pivoted to said third terminal as well as said support portion of third terminal both defining spaces receiving portions of said spring to result in a compact switch arrangement, and said middle portion of said movable contact blade engaging one or the other of said terminal contact portions.

2. The structure recited in claim 1 and further defined by opposed notches formed on the support portion of said third terminal, spaced L-shaped shoulders formed on opposite ends of said movable contact blade and inverted one with respect to the other to prevent lateral movement of said movable contact blade, said L-shaped shoulders including tongue portions received by said notches on opposite sides of said terminal support portion, the space defined by said movable contact blade being between said shoulders.

3. In combination, a circuit breaker including a case, a pair of separable circuit breaker contacts housed within said case, an auxiliary switch within said case and extending partially through said case, said circuit breaker further including linkage means to manually open and close said circuit breaker contacts and to automatically open said circuit breaker contacts upon a predetermined overload, an electromagnetic device for collapsing said linkage means and automatically opening said circuit breaker contacts upon said overload, said auxiliary switch comprising a pair of separable switch contacts and a movable blade carrying one of said switch contacts into and out of engagement with the other switch contact, said linkage means having a portion actuating and maintaining said auxiliary switch actuated when said circuit breaker contacts are closed but not maintaining said auxiliary switch actuated while said overload persists, said portion actuating said auxiliary switch at substantially an invariable predetermined position regardless of any circuit breaker contact wear, said movable blade having a plunger, said linkage means comprising toggle means pivotally connected to a movable arm, said plunger lying along the line of movement of the pivotal connection between said toggle means and said movable arm.

4. The structure in claim 3 wherein said plunger is of electrical insulating material, said movable arm engages said plunger during a portion of the movement of said 6 movable arm between the contacts open and contacts closed position of the circuit breaker contacts and remains in engagement with the plunge-r so long as the circuit breaker contacts are closed.

5. In combination, a circuit breaker including stationary and movable contacts, an auxiliary switch for said circuit breaker, said circuit breaker comprising a linkage including a movable arm carrying said movable contact, said movable arm being pivotally connected by a pin to the remainder of said linkage and movable by said linkage to a predetermined position which remains virtually constant as the stationary and movable contacts wear, said auxiliary switch having a movable blade including an insulator, said insulator engaging a portion of said movable arm directly below said pin during movement of said movable arm between the contacts closed and contacts open positions, whereby the insulator is engaged by said movable arm at a virtually constant portion regardless of circuit breaker contact wear.

6; In combination, a circuit breaker including a case, an auxiliary switch, said circuit breaker further including stationary and movable contacts and a pivotal movable contact arm carrying said movable contact at one end portion said auxiliary switch comprising a movable contact blade, said circuit breaker movable contact arm actuating said auxiliary switch movable contact blade at substantially an invariable, predetermined position of said movable contact arm regardless of the circuit breaker contact wear, said movable contact arm engaging said movable contact blade so long as the circuit breaker contacts are closed but releasing it when the circuit breaker contacts move to the open position, a handle for moving said circuit breaker movable contact arm between the contacts open and closed positions, a toggle mechanism connected between said handle and said movable contact arm by a first pin, said movable contact arm being pivotally connected at its end portion opposite said movable contact, said movable contact being biased to the contacts open position, said first pin being connected to the ends of the latter, said auxiliary switch comprising first and second terminals having shaft portions intermediate their ends, said first and second terminals having contact portions, a third terminal, all three of said terminals having end portions adapted to receive conductors, said third terminal including a support portion for said movable contact blade, a spring connected at one end to said movable contact blade and at the other end to said support portion, an insulator secured to said movable contact blade and extending toward and engageable with the movable contact arm at the Zone of the connection between the movable contact arm and the toggle mechanism but on the side of the movable contact arm opposite to that of the toggle mechanism, the various parts being proportioned so that upon circuit breaker contact closing movement of said handle, the circuit breaker movable contact engages the stationary contact before said toggle mechanism completes its movement, whereby continued movement of the handle in the contacts closing direction closes the contacts while the connection between the movable con tact arm and the toggle mechanism moves down to a predetermined location determined by the handle and toggle mechanism.

References Cited by the Examiner UNITED STATES PATENTS 2,656,439 10/ 1953 Gelheiser et al. 2001l6 2,866,035 12/1958 Coburn 200--l 16 3,098,910 7/1963 Schwartz 200-406 3,137,773 6/ 1964 Black 200--5 3,182,151 5/1965 Coughlin 200-87 ROBERT K. SCI-IAEFER, Primary Examiner.

KATHLEEN H. CLAFFY, Examiner.

M. GINSBU-RG, Assistant Examiner.

Claims

3. IN COMBINATION, A CIRCUIT BREAKER INCLUDING A CASE, A PAIR OF SEPARABLE CIRCUIT BREAKER CONTACTS HOUSED WITHIN SAID CASE, AN AUXILIARY SWICH WITHIN SAID CASE AND EXTENDING PARTIALLY THROUGH SAID CASE, SAID CIRCUIT BREAKER FURTHER INCLUDING LINKAGE MEANS TO MANUALLY OPEN AND CLOSE SAID CIRCUIT BREAKER CONTACTS AND TO AUTOMATICALLY OPEN SAID CIRCUIT BREAKER CONTACTS UPON A PREDETERMINED OVERLOAD, AN ELECTROMAGNETIC DEVICE FOR COLLAPSING SAID LINKAGE MEANS AND AUTOMATICALLY OPENDING SAID CIRCUIT BREAKER CONTACTS UPON SAID OVERLOAD, SAID AUXILIARY SWITCH COMPRISING A PAIR OF SEPARABLE SWITCH CONTACTS AND A MOVABLE BLADE CARRYING ONE OF SAID SWITCH CONTACTS INTO AND OUT OF ENGAGEMENT WITH THE OTHER SWITCH CONTACT, SAID LINKAGE MEANS HAVING A PORTION ACTUATING AND MAINTAINING SAID AUXILIARY SWITCH ACTUATED WHEN SAID CIRCUIT BREAKER CONTACTS ARE CLOSED BUT NOT MAINTAINING SAID AUXILIARY SWITCH ACTUATED WHILE SAID OVERLOAD PERSISTS, SAID PORTION ACTUATING SAID AUXILIARY SWITCH AT SUBSTANTIALLY AN INVARIABLE PREDETERMINED POSITION REGARDLESS OF ANY CIRCUIT BREAKER CONTACT WEAR, SAID MOVABLE BLADE HAVING A PLUNGER, SAID LINKAGE MEANS COMPRISING TOGGLE MEANS PIVOTALLY CONNECTED TO A MOVABLE ARM, SAID PLUNGER LYING ALONG THE LINE OF MOVEMENT OF THE PIVOTAL CONNECTION BETWEEN SAID TOGGLE MEANS AND SAID MOVABLE ARM.