US2695401A

US2695401A - Circuit breaker with signal means

Info

Publication number: US2695401A
Application number: US400898A
Authority: US
Inventors: Broverman Michael
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1953-12-29
Filing date: 1953-12-29
Publication date: 1954-11-23
Anticipated expiration: 1971-11-23

Description

N 1954 M. BROVERMAN CIRCUIT BREAKER WITH SIGNAL MEANS Filed Dec. 29, 1953 2 Sheets-Sheet l I I I Nov. 23, 1954 M. BROVERMAN 2,695,401

CIRCUIT BREAKER WITH SIGNAL MEANS Filed D80. 29, 1953 2 Sheets-Sheet 2 United States Patent- CIRGUIT BREAKER -WITH SIGNAL MEANS Michael Broverman', PittsfieltL'Mass assignor to General Electric Company, acorporation of. New York Application'Decemb'er 29, 1953', Serial No. 400,898

13 Claims; (Cl; 340 -222) 2,487,534 aiwarning light circuit is. provided. When anoverload occurs .in. the electrical system to -be.protected by. the-circuit breaker, the circuit breaker w1ll' operate to close a pair of contacts. in the warning light circuit before thecircuit breakerhas tripped open. Accordingly, .be-

fore the overload trip level of the circuit breaker has been reached, a warning is given-of the presence of an overloadin said electrical system.

When such a type of circuit breaker is used to protect a transformer apparatus, the circuit breaker is positioned inthe transformer tank belowthe oil level. An operating shaft extends through atside wall of the tank and the circuit breaker can. be operated manually from exterially of the transformer tank .by manipulating an operating handle-connected to the exterior end of said shaft.

If the warning light is on and the circuit breaker has trippedopem-the circuitbreaker can be reset and closed and the light canbe put off by first turning the operating handle counterclockwise and. then clockwise. If the warninglight isv on but the circuit breaker has not tripped open, the light can be put. off :merelyby turning the operating handle clockwise. However, the circuit breaker is soconstructed that even when the breaker has tripped open the warning light can still beput off by turning the operating handle clockwise without resetting and closing the circuit breaker. The consequence of this lastmentioned COllditlOI'lxiS that with the light on and the circuit breaker tripped open van operator may put off the warning light but neglect to reset and close the circuit breaker.

It is .anobject of this invention to provide means in the typeof circuit'breaker just described whereby the warning. light cannot be put off. when the circuit breaker has tripped open without first resetting the circuit breaker.

In a circuit breaker provided withv a warning light circuit,said circuit breaker operable to close a pair of contactsin. said circuit before saidcircuit breaker has tripped open, a shaft for manually controlling said circuit breaker,

said shaft rotatable..betweentwo extremes first. inone direction andthen in an opposite direction toreset and close said circuit breaker and open said pair of contacts when said circuit breaker is tripped open, and rotatable in said opposit'edirectionto-open said pair .of contacts when said circuit breaker is tripped vopen or closed, my invention comprises means for prohibiting'rotationiof said shaft in said opposite direction. to open saidpair of contacts when.

said circuit breaker is tripped' open whereby when said circuit. breaker is tripped open saidpair of contacts can be opened only by first resetting said circuit breaker.

In. a circuit breaker.providedwitha warning light circuit, saidlcircuitzbreakeroperable.to close a pair .of con-- tacts insaidzcircuit before said circuit breaker has tripped open, movable. means for controlling said .circuit breaker,

said means movable inone direction to open. or reset said circuit breaker, said meansmovablein an opposite direction to-close saidicircuit. breaker, saidmeans movable in. either: of said d rections .toopen sald, contacts when said.

circuit breaker i3 ciosed or tripped open, .rrny' invention farther comprises nieansfor prohibitingn ovement of said 1 movable -means in said opposite direction to open said contacts'iwhenisaid" circuit breaker is..trippfi=d open where- 2,695,401 Patented Nov. 23, 1954 The invention wiil be better understood by considering:

the followingdescription taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings,'Fig.l is partly broken away, perspectiveview of .an embodiment of my invention when in the warning light on, circuit breaker trippedopen position. Fig.2 is a sectional view taken along the line 22 of Fig. 1. Fig. 3 is another view'of the apparatus shown in Fig. 1 when in the warning light otf, circuit breaker reset and open position. Fig, 4 isstill another view of the apparatus shown in Figs; 1 and 3 when in the warning light off, circuit. breaker'reset and closed position. Throughout the various figures like :reference numerals will. be used to indicate identical parts.

Referringnow to the drawings, and more particularly to Fig. l, illustrated therein is a circuit breaker 10 adapted to protect a transformer 11 or other electrical apparatus contact 12 is carried by the forward end of a switch arm.

14. Switch arm 14 is pivotally mounted adjacent its rear end on a shaft 15. Stationary contact 13 is con-v nected to and in electrical contact with the forward end of a bimetallic element 16. The forward end of.bi-.

metallic element 16 is rigidly fixed and the rear end of bimetallicelement .16 is free whereby said rear end is adapted to bedeflected upwardly upon an overcurrent through bimetallic element 16. Movable contact 12,.

stationary contact 13, and bimetallic element 16 are electrically positioned in'a secondary winding lead 17 of transformer 11. In Fig. l circuit breaker 10'is shown in its tripped open position wherein contact 12 and 13 .are disengaged. As will. be more clear hereinafter, when an overcurrent or thelike occurs in the secondary winding lead 17 of transformer 11 the rear end of bimetallic element 16 will be deflected upwardly and contacts 12 and 13 willbe snapped from: their circuit closed position to their circuit open position. Also, as will be obvious to those skilled .in .the art,

elements

12, 13, 14 and 16 are duplicated, not shown, on the right hand side of circuit breaker 10 for response to an overcurrent or the like in another secondary winding-lead 18 of the transformer 11.

Still referring toFig; l, circuit breaker 10 is provided with a signalv circuit comprising, light 20, a stationary'contact 21, contact 22. are illustrated in their engaged position whereby the warninglight 20 is on. As will be clearer hereinafter, circuit breaker "10 is constructed so that

contacts

21 and 22 are tripped'to'theircircuit closed position prior to tripping open of the

circuit breaker contacts

12 and 13 whereby a visual indication is given of 'an overload condition inthe transformer 11 .prior to tripping: open of the

circuit breaker contacts

12 and 13.

and a movable rod-like Referring now also toFig. 3 of the drawings, circuit.

contact..22 is carried .b'yan elongated bar .30 disposed substantially perpendicular to Iod-likejmovable contact 22 and the .latchingrbar .23; Movableacontact. 22 and'elom gated .I.bar. 30. are connected. together by welding or the like'andelongatedibar 30 is' biased downwardly and'rear-' wardl'y'byan iricliriedspring 315 Rearward'movement of .1

for example, a warning In Fig.

l'warning'light contacts

21 and 22 elongated bar 30 is limited by an adjustable stop 32. Vertical upward and downward movement is imparted to rod-like movable warning light contact 22 by virtue of a vertically extending guide slot 33 formed in one leg I portion of an inverted U-shaped support member 34, only a portion of which is shown. Much of inverted U- shaped support member 34 has been broken away in Fig. 1 for purposes of clarity. However, as will be obvious to those skilled in the art, the other not shown leg portion of support 34 is provided with a vertically extending slot similar to slot 33 for guiding the left-hand end of rod-like movable warning light contact 22. Also, a slot, not shown, is formed in the cross piece or base portion of inverted U-shaped support 34 to aid in steadying and guiding elongated bar 30.

In Fig. 3, wherein the circuit breaker is shown in its reset but contacts open position, the elongated bar 30 is illustrated as having been raised upwardly whereby its lower end rests upon the upper surface of latching plate 26. In this raised position of bar 30, spring 31 holds bar 30 against the adjustable stop 32. In such raised position of bar 30 movable contact 22 is disengaged from the stationary contact 21 whereby the light 20 is off.

As seen in Fig. l, the free or rear end of the bimetallic element 16 carries a finger 35. Finger 35 is adapted to engage an integral projection 36 on the latching bar 23. As hereinbefore stated, when an overcurrent occurs in the secondary winding lead 17, the free or rear end of bimetallic element 16 is deflected upwardly. Upward deflection of the rear end of bimetallic element 16 causes finger 35 to engage integral projection 36 whereby the latching bar 23 is rotated counterclockwise against the clockwise biasing action of spring 25, shown only in Fig. 3. When latching bar 23 is rotated counterclockwise the latching plate 26 is moved out of the downward path of movement of the elongated bar 30. Thereafter the lower end of elongated bar 30 is free and clear of the latching plate 26 whereby spring 31 can cause downward movement of elongated bar 30 from the position illustrated in Fig. 4 to the position illustrated in Fig. l. When'elongated bar 30 moves downwardly the

warning light contacts

21 and 22 are engaged to put the light 20 on inasmuch as movable contact 22 gnovgs) downwardly simultaneously with the elongated As seen from Figs. 1 and 3, positioned forwardly of the elongated bar 30 is an inverted generally U-shaped member 40 having obtuse angle-shaped legs, only one of which is shown. The apexes of said angle-shaped legs point rearwardly and the lower ends of said legs are pointed in an acute V-shaped manner. Said pointed leg ends are positioned in acute V-shaped pivot grooves 41, only one of which is shown, formed in the previously mentioned but not shown insulating material base whereby the U-shaped member 40 can be pivoted about its pointed leg ends forwardly or rearwardly within grooves 41. A horizontally extending arm 42 is connected at its forward end by a rivet 43 or the like to one side of the inverted generally U-shaped member 40. The connection between the horizontally extending arm 42 and U- shaped member 40 is a lost motion connection by virtue of a slightly convex curved and generally horizontally extending slot 44 formed within the forward end of arm 42 within which the rivet 43- is free to move.

Carried by the rear end of arm 42 is an upright U-.

shaped member 45. U-shaped member 45 underlies the rod-shaped movable warning light contact 22 and the legs of U-shaped member 45 diverge away from each other along opposite sides of the movable warning light contact 22. 1

In Fig. 1 the warning light 20 is on and the circuit breaker has tripped open. To reset' and close the circuit breaker and put the warning light 20 off, it is intended that the inverted U-shaped member 40 first be pivoted rearwardly and then forwardly. Upon initial rearward movement of U-shaped member 40 the lost motion connection 43, 44 between

members

40 and 42 is taken up. Further rearward movement of member 40 causes arm 42 to move rearwardly whereby the for li'ght 20 off but the

circuit breaker contacts

12 and 13 .80 ward leg of U-shaped member 45 will engage the rod'- like movable contact 22 and move contact 22 upwardly to open the warning light circuit. In Fig. 3 the circuit: breaker 10 is shown as having been reset with the warning J still open. To close the

circuit breaker contacts

12 and 13 the U-shaped member 40 is now pivoted forwardly. When the U-shaped member 40 is pivoted forwardly the lost motion connection 43, 44 is first taken up and then upon completion of forward movement of U-shaped member 40, the arm 42 will be moved forwardly slightly and the rear leg of U-shaped member 45 will engage movable contact 22. The final position of U-shaped member 40 upon completion of its forward movement is illustrated in broken-line outline in Fig. 4. A spring 46 biasing the arm 42 rearwardly will move the arm 42 and U-shaped member 40 rearwardly slightly after the completion of said forward movement of U-shaped member 40 to insure that the rod-like movable warning light contact 22 lies midway between the diverging legs of upright U-shaped member 45. The wisdom of such an arrangement is that if the bimetallic element 16 should be deflected upwardly slightly to free the elongated bar 30 for downward movement to close the warning light circuit when the condition of overload has not reached a high enough level to trip the circuit breaker contacts- 12 and 13 open, the warning light 20 can be put off as soon as the overload condition is removed, merely by pivoting member 40 forwardly from its full-line position in Fig. 4 to its broken-line position whereupon the rear leg portion of U-shaped member 45 will engage contact 22 to open the warning light circuit and put off the light 20. However, the disadvantage of such an arrangement is that even when the circuit breaker 10 has tripped open an operator is apt to put off the warning light 20 without first resetting the circuit breaker merely by moving the U-shaped member 40 forwardly. As will be more clear hereinafter, in my invention I provide means whereby the U-shaped member 40 cannot be,

moved forwardly or clockwise to open the warning light circuit when the circuit breaker 10 has tripped open. That is, if the circuit breaker has tripped open an operator can put off the warning light 20 only by first pivoting the U-shaped member 40 rearwardly or counterclockwise to reset the breaker.

Referring again to Fig. l, disposed between the legs of U-shaped member 40 is an inverted generally Y- shaped reset member 50 having three legs or arms 51, 52 and 53. Generally Y-shaped reset member 50 is pivotally connected adjacent the lower end of leg 52 to a shaft 54 fixed in the not shown previously mentioned insulating material base. An arm 55 is pivotally connected at an upper end thereof to the upper end of leg 52 adjacent the forward edge of reset member 50. Another arm 56 is piv tally mounted at the lower end thereof to a shaft 57 fixed in switch arm 14. The lower end of arm 55 and the upper end of arm 56 are each pivotally connected to a freely movable or floating shaft 58. Leg 51 of reset member 50 extends rearwardly and the upper end thereof is disposed behind the cross-piece or base of U-shaped member 49. A spring 59 is connected at opposite ends thereof to a rear portion of said cross-piece or base of member 15 is a latching mechanism comprising three

curved levers

60, 61, and 62; and a generally semi-circular cam 63 having a latching tooth 64 therein.

The circuit breaker 10 for transformer 11 can be controlled from exteriallv of a transformer tank, not shown, enclosing circuit breaker 10 and transformer 11, by properly manipulating an operating handle 70 connected to the exterior end of an operating shaft 71. An aperture is formed in a side wall 72 of the transformer tank and through said aperture extends an operating shaft guide bushing or hearing 73. Handle 70 has a pointer 74 formed integrally thereon cooperative with a suitably marked dial plate portion 75. Adjacent a central portion of the operating shaft guide bushing or bearing 73 is formed an external shoulder 76 facing the exterior surface of side wall 72. The central portion of guide bushing or hearing 73 positioned interially of the not shown transformer tank has threads formed thereon cooperative with an internally threaded nut 77. When nut 77 is turned down on the central threaded portion of guide bushing or hearing 73' a' gasket or other sealing means positioned between external shoulder 76 and the exterior surface of side wall 1' will be compressed to seal the aperture in the transformer tank side wall 72; The interior'end of operating shaft" s '71 is connected to the inverted U-shaped member 40. by anadjustable linkage'78, 7-9. When the;operating handle 70 is'rotated clockwise the inverted U-shaped member 40 is simultaneously pivoted clockwise or forwardly, and

when operating handle 70 is rotated counterclockwise the inverted U-shaped member 40 is simultaneously pivoted counterclockwise or rearwardly.

As illustrated in Fig. '1, the circuit breaker 10 has tripped open whereby the circuit breaker contacts 12 and 13areopen and the Warning

light contacts

21 and 22 are closed whereby the warning light 20 is on. To close the

circuit breaker contacts

12 and 13, the latching mechanism fill-64 and the reset member 50 of the circuit breaker 10 must first be reset. This is' accomplished by rotating the handle 70 counterclockwise until pointer 74 is at the A position of dial 75 whereby the U-shaped member 40 will be caused to rotate counterclockwise or rearwardly. As illustrated in .Fig. 3, when member 40 is rocked counterclockwise or rearwardly, the reset member 50 is simultaneously rocked counterclockwise or rearwardly about its pivot 54 inasmuch as the leg 51 and rear-portion of the cross piece or base portion of U-shaped member 40 are in abutting relationship when the circuit breaker 10 has 'trippedopen asillustrated in Fig. l. Counter-clockwise pivotal movement of the reset member 50 causes the leg 53 to move rearwardly and downwardly whereby the latching tooth 64 of. the cam 63 is placed in contact with the upper surface of latching plate 26 as shown in vFig. 3.. Simultaneously, the horizontally extending arm 42 ismoved rearwardly, whereby the forward leg of upright U-shaped member 45 strikes the movable rod-like contact 22 to disengage the warning light contacts '21 and 22 and raise the elongated bar 30 whereby the spring 31 can pull the elongated bar 30 against the adjustable stop 32. When the elongated bar 30 is raised upwardly and pulled rearwardly t1 e lower end thereof will be placed in contact with the upper surface of latching plate 26 as illustrated in Fig. 3. It should be noted that a larger portion of the latching tooth 64 is in engagement with the latching plate 26 than there is of the lower end of the elongated bar 30 in engagement with latching plate 26. Since a smaller portion of the lower end of elongated bar 39 is in engagement with the latching plate 26 than there is of the latching tooth 64, when the bimetallic element 16 deflects upwardly the elongated bar will be released for downward movement before the latching tooth 64-is disengaged from the latching plate 26. Thereby, provision is made for closing of the warning

light contacts

21 and 22 before the circuit breaker has tripped open.

As seen from Fig. 1, when the latching mechanism 69-64 and the reset member 50 have been tripped to their circuit breaker tripped open position, the pivot point 65 between the upper end of arm 55 and the reset member $50 is disposed forwardly of the pivot point or shaft 54 for the reset'rnember 50 adjacent the lower end of leg-52. However, when the reset member 50 is rocked counterclockwise or rearwardly, the pivot point 65 is caused to move rearwardly and downwardly whereby after the latchingmeclianism 6064 hasbeen latched the pivot point 65 is disposed rearwardly of the pivot point 54, as shown in Fig. 3. .Also, as illustrated in Fig. 3, when the circuit'breaker is in its reset c ntacts open position the spring 59 is disposed rearwardly of the arm 55 and the reset member, 50 is held-in its latched position by virtue of the engagement of latching tooth 64 with latching plate 26.

After the latching mechanism 60-64 and reset member 50 of the circuit breaker have been reset by counterclockwise 'movement of the handle 70, the

circuit breaker contacts

12 and 13 can be closed by moving the pointer74 clockwise to the 13 position of dial plate 75. Referring now to Fig. 4, it will be seen that when the U-shaped member 40 is rocked .clockwise or forwardly the spring 59 will be moved to a position forwardly of the pivot point 65 of the upper end of 'arm 55. Accordingly, the buckled or collapsed

lever arms

55 and 56 illustrated in Fig. 3 will now be snapped to an extended position illustrated in Fig. 4 Wherebythe switch arm 14 is snapped clockwise and downwardly for engagement of the movable circuit breaker contact 12 with the stationary'circuit breaker contact 13. 'When the .U shaped member 40 is :rockedclockwise. 'or :forwardly to :close ithecircuit breaker .contaetsglizand 1:3,

simultaneously "the arm "42 sis-pulled :forwardly to .cause therear leg :of 'U-s'haped member -45 to come in contact with the movable contact The extreme forward position of U-shaped member 40 upon clockwise rotation 'of op'erating handle 70. is illustrated in broken-line outline inFig. 4. At the extreme end of this forward movement of member 40, the spring 46 will retract member 40 from the. broken-line position to the full line position illustrated in Fig. 4. This action also retracts the horizontally extending arm 42 rearwardly slightly so that therear leg of .U-shaped member 45 no longer contacts the movable warning light contact 22. As seen in Fig. '4, the spring 59 will not cause the

arms

55 and 56 to buckle .in .an opposite direction from the buckled :position of arms- 55 and :56 shown. in Figs. 1 and 3 inasmuch as arm .55 in the Fig. 4 position of the circuit breaker will abut a stop 66 provided on fixed shaft 54.

When the transformer 11 is overloaded the bimetallic element 16will deflect upwardly and cause the latching bar 23 and plate 26' to pivot .counterclockwise. Initial counterclockwisepivotal movement of the latching plate 26 will release the elongatedbarSO-for downward movement whereby the warning :light contacts 21 and '22 are engaged'toput on the warning light 20 before the latching tooth 64 is disengaged from the latching plate 26 to trip the

circuit breaker contacts

12 and 13 open. As hereinbefore explained, the warning light 20 can be put off by pivoting operating handle 70 clockwise to move I the U-shaped member 40 from the full-line position illustrated in Fig. '4 to the broken-line position illustrated in Fig. 4 while the

circuit breaker contacts

12 and 13 are still in the circuit closed position. Movement of the U-shapedmember 40 from the Fig. 4' fullline position to the 'Fig. 4 broken-line position will move the horizontally extending arm 42 forwardly to engage the rear leg of U-shaped member 45 with the movable contact 22 to raise movable contact 22 from engagement with the stationary warning light contact 21 whereby the warning light 20 is put ofi. After the warning light is put off, the spring 46 will retract the U-shaped member 40 from the Fig. 4 broken-line position to the Fig. 4 full-line position. Also, spring 46 moves arm 42 rearwardlyslightly to disengage the rear leg of U-shaped member 45 from the then raised movable warning light contact 22.

When going from the reset circuit breaker contacts open position illustrated in Fig. 3 to the circuit breaker contacts closed position illustrated in Fig. 4, the buckled

arms

55 and 56 were placed in their extended position illustrated in Fig. 4. When

arms

55 and 56 were extended the spring 59 tended to move the arm 55 upwardly. An upward thrust on arm 55 tends to move the reset member 50 upwardly also. However, due to the configuration of member 50 and the pivotal mounting of member 50 at pivot point 54 positioned in front of the pivot point 65 this upward thrust on arm 55 is translated into a thrust against reset member 50 tending to rotate member 50 clockwise or forwardly. However, reset member 50 is prohibited from rocking clockwise or forwardly by virtue of engagement of latching tooth 64 and latching plate 26. Should a sufficient overload condition develop in the transformer 11 to trip the latching mechanism 64 as well as the elongated bar 30, the pivot point will move forwardly of the spring59. Thereafter, the

arms

55 and 56 will have been buckled and the spring 59 will be free to snap the switch arm 14 open to the tripped open position illustrated in Fig. 1. When the circuit breaker trips open from the Fig. 4- position to the Fig. 1 position, the pivot point or shaft 58 is disposed rearwardly of the center-line of the V-shaped pointed ends of the legs of the U-shaped member 40. Accordingly, the spring 59 will pull the U-shaped member 40 rearwardly or counterclockwise slightly.

As 'hereinbefore stated, when the circuit breaker 10 trips open the ,pivot point 65 is disposed forwardly of the pivot point :54. .Accordingly, after the circuit breakor has tripped open, the'circuit breaker cannot be closed by rocking the operating handle and U-shaped member 40 clockwise. In Order 'to close the

contacts

12 and 13, the spring 59;must bemoved forwardly of the pivot point 65. However, suchalarge degree of forward movement of U1shaped ;rnember 40 is prohibited by virtuemf'them peration between, the 'Vishaped tends of the legs of U-shaped member 40 and the V-shaped pivot grooves 41. When the circuit breaker has tripped open if the U-shaped member 40 is rocked forwardly, the forward edge of the V-shaped ends of the legs of U-shaped member 40 will engage the forward edges of the V-shaped pivot notches 41. Thereafter, forward movement of U-shaped member 40 is prohibited. At such extreme forward movement of the U-shaped member 40, the spring 59 has still not moved forwardly enough to be positioned in front of the pivot point 65 to distend the

arms

55 and 56 to snap the switch arm 14 downwardly whereby the movable circuit breaker contact 12 is engaged with the stationary circuit breaker contact 13. However, even though the circuit breaker cannot be closed by clockwise movement of handle 70 once the circuit breaker has tripped open, still the warning light 20 can be put off by clockwise rotation of handle 70 and U-shaped member 40. For instance, viewing Fig. 1, it will be seen that if U-shaped member 40 is rocked forwardly slightly the horizontally extending arm 42 will also be moved forwardly whereby the rear leg of U-shaped member 45 will engage and raise the movable warning light contact 22 to open the warning light circuit. Opening of the warning light circuit by a slight clockwise movement of the operating handle 70 is desirable for as explained in conjunction with Fig. 4, it is desirable for an operator to be able to open the warning

light contacts

21 and 22 after the overload condition has been removed by a slight clockwise pivotal movement of the U-shaped member 40 when the circuit breaker has not tripped open. In my invention, I providemeans for prohibiting opening of the warning

light contacts

21 and 22 by clockwise movement of handle 70 when the circuit breaker has tripped open to the Fig. 1 position, yet still permitting opening of said warning light contacts by clockwise movement of operating handle 70 when the

circuit breaker contacts

12 and 13 are in their closed position.

The locking means for prohibiting clockwise movement of operating shaft 71 and member 40 when the circuit breaker 10 has tripped open to apprise an operator of the fact that the circuit breaker 10 has tripped open comprises a circular disc or cam 80 which abuts the interior end of guide bushing or bearing 73. Disc or cam 88 is connected to shaft 71 for rotary movement therewith by virtue of a pin 81 or the like. Disc or cam 88 has an outer diameter greater than the outer diameter of bushing or bearing 73. a A rectangular-like tab or finger 82 flush with the outer cylindrical surface of cam 80 and approximately perpendicular to the lefthand side of cam 80 extends therefrom'in overlying or superposed relationship with the exterior cylindrical surface of the interior end of bushing or bearing 73. Positioned on the interior end of bushing or hearing 73 between the exterially threaded shoulder 83 of bushing 73 and cam 88 is a cylindrical or sleeve-like cam 84-. Between the cam 84 and shoulder 83 is a spring 85 continuously biasing cam 84 against cam 80.

In the right-hand end edge of cam 84 opposite to the cam 88 and opposite to the tab or finger 82 is formed a generally L-shaped notch 86. The longer leg portion of notch 86 is positioned along said right-hand end edge of cam 84 and the base leg portion of notch 86 extends away from said right-hand end edge of cam 84. The depth of the longer leg portion of notch 86 is less than the length of rectangular-like tab 82, whereas the depth of the base leg portion of notch 86 is greater than the length of tab 82. The base edge 87 of L-shaped notch 86 is inclined or tapered with respect to the longer leg portion of notch 86 at an angle of approximately 60 for a purpose hereinafter to be described.

In the left-hand end edge of cam 84 approximately diametrically opposite to the notch 86 is formed another generally L or right-angle shaped notch 88. The shorter leg portion of notch 88 extends from said left-hand end edge of cam 84 towards the right-hand end edge of cam 84 and is disposed with respect to said left-hand end edge of cam 84 at an angle of approximately 60 generally parallel to the base edge 87. The longer leg portion of notch 88 extends from the interior end of the shorter leg portion of notch 88 approximately perpendicular to the axis of sleeve-like cam 84. A stop pin'89 connected to the bushing or bearing 73 is disposed within the notch 88' for a purpose hereinafter to be described. As illustrated in Fig. 1, when the circuit breaker is in the tripped open position the tab 82 is disposed within the shorter leg portion of notch 86 and the stop pin 89 is disposed within the shorter leg portion of notch 88. Inasmuch as cam 80 is pinned to shaft 71 and tab 82 is disposed within the shorter leg portion of notch 86, should an operator attempt to rotate the operating handle 70 clockwise to put the warning light 20 off, the sleeve-like cam 84 will be jammed against the stop pin 89 inasmuch as the base edge 98 of notch 88 is in abutting relationship with respect to the stop pin 89. Accordingly, when the circuit breaker 10 is in the tripped open position, the warning light 20 cannot be put off by pivoting handle 78 and member 40 clockwise. With the operating handle 70 locked against clockwise movement an operator is apprised of the fact that the circuit breaker 10 has tripped open and that he must first reset the circuit breaker 10 by rotating the operating handle 70 counterclockwise. When the operating handle 70 is rotated counterclockwise, the tab 82 engages the inclined base edge 87 of notch 86 and imparts a counterclockwise motion to cam 84 and simultaneously moves cam 84 away from cam 80 whereby the spring is compressed. Movement of the cam 84 counterclockwise and away from cam 80 causes the stop pin 89 to ride up the inclined shorter leg portion of notch 88 and then into the longer leg portion of notch 88 to the position illustrated in Fig. 3. When the stop pin 89 reaches the closed end of the longer leg portion of notch 88 as illustrated in Fig. 3, further counterclockwise movement of operating handle 70 is prohibited by stop pin 89 and the circuit breaker 10 is now in its reset position. With the stop pin 89 disposed within the longer leg portion of the notch 88 the spring 85 is prohibited from moving the cam 84 into contact with the left-hand side of cam 88. To close the

circuit breaker contacts

12 and 13 after the circuit breaker has been reset, the operating handle 70 is now rotated clockwise. When the operating handle 70 is rotated clockwise, the tab 82 will strike the edge 91 of notch 86 and rotate the cam 84 clockwise whereby the stop pin 89 will be removed from the longer leg portion of notch 88 into the shorter leg portion of notch 88. After the handle 70 is rotated clockwise to move the member 40 from the Fig. 3 position to the broken-line position illustrated in Fig. 4, the stop pin 89 will abut the base edge 98 of notch 88 whereby further clockwise movement of the operating handle 70 is prohibited. The spring 85 as yet cannot move the cam 84 against the cam 80 inasmuch as the tab 82 is still disposed within the longer leg portion of notch 86. When the member 40 is moved to the broken-line position illustrated in Fig. 4, the spring 46 will retract member 40 to the full-line position illustrated in Fig. 4 whereby a slight counterclockwise motion will be imparted to the operating shaft 71. Said slight counterclockwise motion of shaft 71 moves the tab 82 slightly counterclockwise away from the edge 91 of notch 86. However, the spring 85 still will not move the cam 84 against the cam 80 inasmuch as the tab 82 is still disposed within the longer leg portion of notch 86. Should the

warning light contacts

21 and 22 in Fig. 4 be closed to place the warning light 20 on while the

circuit breaker contacts

12 and 13 are still closed, the warning light 20 can be put off by rotating the operating handle 70 clockwise. Upon clockwise rotation of operating handle 70 the tab 82 will move from the position illustrated in Fig. 4 against the edge 91 of notch 86. Upon such clockwise rotation of shaft 70, the U-shaped member 48 of Fig. 4 will be moved from the full-line position to the broken-line position to open the warning

light contacts

21 and 22 after which the spring 46 will retract the member 40 rearwardly slightly causing the tab 82 to move counterclockwise from a position of abutting relationship with the edge 91 of notch 86 to the nonabutting position shown in Fig. 4. As hereinbefore described with reference to Fig. 4, when the circuit breaker 10 trips open the U-shaped member 40 is rocked counterclockwise slightly from the Fig. 4 full-line position. counterclockwise rotation of member 40 from the fullline position illustrated in Fig. 4 causes the tab 82 to move counterclockwise opposite to the shorter leg portion of notch 86. When the tab 82 is disposed opposite to the shorter leg portion of notch 86, the cam 84 is then free to be moved against cam 80 by the spring 85 inasmuch as the stop pin 89 is disposed without the longer leg portion of :notch 88 and within the shorter leg portion. of notch 88. Accordingly,xwhen the. circuit. breaker v10. tripsopeni the spring 85 will drive the cam 84. towards cam. 8fl whereby- 'thertab. 82 will be disposed within the shorter leg portiozrof notch 86 as illustrated in the Fig. 1 position of the locking cam means As illustrated in Fig. 1, when the spring 85 drives the cam 84 against the cam 80 to position the tab 82 within the shorter leg portion of notch 86, the stop pin 89' is disposed in abutting relationship with respect to the edge 90 of notch 88 whereby the operating handle 70 cannot be rotated clockwise to turn the warning light 2070i? without first rotating, the operating handle 70 counterclockwise to reset the circuitbreaker 10.

While there has been shown: and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without'd'eparting from the-invention, and it is intended by the appended claims to cover. all such changes and modifications as: fall within the true spirit and scope "of the invention.

What I claim asv new and desire to secure by Letters Patent of the United States is:

1. A circuit breaker provided with. a signal: circuit, said circuit breaker operable to close a pair of. contacts in saidsignalcircuit before saidcircuit breaker has tripped open, means movable in oppositedirections for controlling said circuit breaker, said means movable only first in one direction and then in another direction to close said circuit breaker when in a tripped open. position, and

movable in said another. direction to open said. pair of.

contacts only when said circuit breaker isclosed.

2. A circuit breaker provided with a signalcircult, said circuit breaker operable to close a pair of contacts in said signal circuit before said circuit breaker has tripped open, movable means for resetting said circuit breaker when in a tripped open position and for opening, said contacts when said contacts are closed, said means actuatable only in one directionto reset said breaker, said means actuatable in either said one or another directionto open said contacts, and other means prohibitingmovement of said movable means in said another direction when said circuit breaker is in a tripped open position.

3. In a circuit breaker having a warning light circuit, said circuit breaker operable to close said warning light circuit prior to tripping open of said circuit breaker, a shaft for resetting saidcircuit breaker after said circuit breaker has tripped open and for opening. said warning.

light circuit before and after said circuit breaker has tripped open, said circuit breaker when in the tripped open position reset only by first rotating said shaft in one direction, said light circuit when closed opened by rotating said shaft in said one direction or another direction opposite to said one direction, locking means for prohibiting rotation of said shaft in said another direction when said circuit breaker is in a tripped open position whereby said shaft can only be first rotated in said one direction when said circuit breaker is in a tripped open position.

4. In a circuit breaker having a pair of circuit breaker contacts, a reset member cooperative with a latching mechanism whereby said circuit breaker contacts can be closed only after said reset member is moved from a tripped position to a reset position whereby said reset member is locked by said latching mechanism in said reset position, said' circuit breaker having a pair of warming light contacts, said circuit breaker operable to close said warning light contacts prior to unlocking of said latching mechanism when said circuit breaker contacts are closed, said circuit breaker having means for moving said reset member from said tripped position to said locked reset position and for opening said warning light contacts only with simultaneous movement of said reset member from said tripped position to said locked reset position or subsequent to said movement while said reset member is in said locked reset position.

5. In a circuit breaker having a warning light, said circuit breaker operable to put said warning light on prior to tripping open of said circuit breaker, a shaft for manually operating said circuit breaker, said shaft rotatable only in one direction to reset said circuit breaker when said circuit breaker has tripped open, said shaft rotatable in either said one direction or another direction opposite to said one direction to put said light ofi when said light is on, means for prohibiting rotation of said shaft in said another direction when said circuit breaker has tripped open. comprising: av stationary bushing. for said. shaft,, a cam. connected. to. said shaft. and. rotatable therewith,-a movable cam on saidbushing continuously urgedagai'nst said shaftzconnectedcam, said shaft connectedcarn having a tab thereon cooperative with a notch in said movable cam, and another notch in said movable cam cooperative with a stop member connected to said bushing.

6. In a circuit breaker adapted to protect an electrical apparatus from an overload, said circuit breaker having signal means, said circuit breaker adapted to actuate said signal means. from a non-indicating condition to an indicating; condition upon an overload in said electrical; apparatus prior to tripping open of said circuit breaker, movable means. for manually operating, said circuit breaker, said circuit breaker when in a tripped open position reset only by actuating said movable means in one direction, said signal means when in an. indicating condition returnable to a non-indicating condition by actuating said movable means either in said one direction or in: another directoin opposite to said one direction, and means for prohibiting actuation of said movable meansv in said another direction when said circuit breaker is in a tripped open position whereby when said circuit breaker is in a tripped open position said signal means can be returned to said-non-indicating condition only by actuating said movable means in said one direction whereby said circuit breaker will be simultaneously reset.

7. In acircuit breaker adapted to protect an electrical system from an overload, said circuit breaker having asignal means, said circuit breaker adapted to actuate saidv signal means from a non-indicating condition to an indicating condition upon the occurrence of an overload in said electrical system prior to tripping open of said circuit breaker froma reset closed position, a movable control member connected to said circuit breaker for controlling said circuit breaker and signal means, said circuit. breaker when in a tripped open position returnable to a reset closed position only by first actuating said control member in one direction and then in another direction'oppostte to said one direction, said signal means when in an indicating condition returnable to said non-indicating condition by actuating said control member either in said one direction or said another direction, and locking means comprising a stop member for prohibiting actuation of said control member in. said another direction when said circuit breaker is in a tripped open position while still permitting actuation of said control member in said another direction when said circuit breaker is in a reset closed position whereby when said circuit breaker is in a tripped open position said signal means can be returned.

to said non-indicating condition only by actuating said control member in said one direction whereby said circuit breaker will be simultaneously returned from a tripped open position-to a reset position.

8. In a circuit breaker adapted to protect an electrical apparatus from an overload, said circuit breaker having, signal means, said circuit breaker adapted to actuate said signal means from a non-indicating condition to an indicating condition upon the occurrence of an overload in said electrical apparatus prior to tripping open of said circuit breaker from a reset closed position, an operating shaft for operating said circuit breaker and signal means, said circuit breaker when in a tripped open position returnable to a reset closed position only by first rotating said shaft in one direction and then in another d1rect1on opposite to said one direction, said signal means when in an indicating condition returnable to said nonindicating condition by rotating said shaft in either said one direction'or said another direction, and lock-ing means for prohibiting rotation of said shaft in said another direction when said circuit breaker is in a tripped open position whereby when said circuit breaker is in a tripped open position said signal means can be returned to said non-indicating condition only by first rotating said shaft in said one direction whereby said circuit breaker will be simultaneously reset, said locking means comprising an immovable bearing for said shaft, a circular cam fixed to said shaft and rotatable therewith, a movable sleevelike cam on said bearing continuously urged for movement against said circular cam, said circular cam having a tab thereon cooperative with a notch in said movable sleeve-like cam, and another notch in said movable sleeve-like cam cooperative with a stop member fixed to said immovable bearing.

9. In a circuit breaker adapted to protect an electrical apparatus from overloads, said circuit breaker havinga warning light, said circuit breaker adapted to put sa d warning light on upon the occurrence of an overload 111 said electrical apparatus prior to tripping open of said circuit breaker from a reset closed position, a shaft connected to said circuit breaker for manually operating said circuit breaker and warning light, said circuit breaker when in a tripped open position returnable to a closed position only by first rotating said shaft counterclockwise to reset a tripping mechanism in said circuit breaker after which said circuit breaker can be closed by then rotating said shaft clockwise, said warning light when on put off by rotating said shaft either counterclockwise or clockwise when said circuit breaker is either in a tripped open position or in a reset closed position, locking means comprising a 'stop member for prohibiting clockwise rotation of said shaft when said circuit breaker is in a tripped open position while still permitting clockwise rotation of said shaft when said circuit breaker is in a reset closed position whereby said warning light can be put off when said circuit breaker is in a tripped open position only by rotating said shaft counterclockwise and simultaneously resetting said tripping mechanism.

10. In a circuit breaker adapted to protect an electrical apparatus from overloads, said circuit breaker having a warning light, said circuit breaker adapted to put said warning light on upon the occurrence of an overload in said electrical apparatus prior to tripping open of said circuit breaker from a reset closed position, a shaft connected to said circuit breaker for manually operating said circuit breaker and warning light, said circuit breaker when in a tripped open position returnable to a closed posit-ion only by first rotating said shaft counterclockwise to reset a tripping mechanism in said circuit breaker after which said circuit breaker can be closed by then rotating said shaft clockwise, said warning light when on put off by rotating said shaft either counterclockwise or clockwise when said circuit breaker is either in a tripped open position or in a reset closed position, locking means for prohibiting clockwise rotation of said shaft when said circuit breaker is in a tripped open position while still permitting clockwise rotation of said shaft when said circuit breaker is in a reset closed position whereby said warning light can be put off when said circuit breaker is in a tripped open position only by rotating said shaft counterclockwise and simultaneously resetting said tripping mechanism, said locking means comprising an immovable bearing for said shaft, a circular cam fixed to said shaft and rotatable therewith, said bearing having a sleeve-like movable cam thereon continuously urged towards said circular cam, a tab connected to said circular cam and extending therefrom into a generally L-shaped notch formed in an edge of said sleevelike cam opposite to said circular cam, a base edge portion of said notch inclined with respect to said end edge at an angle of approximately 60 degrees, another generally L-shaped notch formed in another end edge of said sleeve-like cam, a base leg portion of said another notch inclined with respect to said another end edge at an angle of approximately 60 degrees, and a stop pin fixed to said bearing and disposed within said another notch.

11. In a shaft journaled within a bearing for rotation in one direction and in another direction opposite to said one direction, means for prohibiting rotation of said shaft in said another direction after said shaft has rotated beyond a predetermined point in said one direction, said means comprising a cam fixed to said shaft and rotatable therewith, a movable cam on said bearing, said movable cam continuously urged for movement towards said shaft fixed cam, said shaft fixed cam having a tab extending? therefrom into a notch formed in said movable cam opposite to said tab, said movable cam having another notch formed therein, and a stop member fixed to said bearing disposed within said another notch.

12. In a shaft journaled within a stationary bearing for rotation in opposite direction-s between two extremes, said shaft rotatable in one direction from one of said extremes to another of said extremes and rotatable in another direction opposite to said one direction from said another extreme to said one extreme, locking means for prohibiting rotation of said shaft in said another direction after said shaft has been rotated in said one direction from said one extreme beyond a predetermined point disposed between said two extremes without first rotating said shaft in said one direction to said another extreme, said locking means comprising a cam fixed to said shaft and rotatable therewith, a movable cam on said bearing continuously urged for movement towards said shaft fixed cam, a finger extending from said shaft fixed cam into a notch formed in said movable cam opposite to said finger, another notch formed in said movable cam, and a stop member fixed to said bearing disposed within said another notch.

13. In a shaft journaled for clockwise and counterclockwise rotation in a stationary cylindrical bearing between two extremes, locking means for prohibiting clockwise rotation of said shaft after said shaft has been rot-ated counterclockwise from one of said extremes past a point disposed between said two extremes without first rotating said shaft counterclockwise to another of said extremes, said locking means comprising an annular cam having an outer diameter greater than an outer diameter of said cylindrical bearing fixed to said shaft and rotatable therewith, a rectangular-like tab extending from said cam into superposed relationship with an outer cylindrical surface of said cylindrical bearing, a movable sleeve-like c am positioned on said cylindrical bearing, a spring continuously biasing said movable cam towards said annular cam, a first generally L-shaped notch formed in an end edge of said'movable cam opposite to said annular cam, a longer leg portion of said notch extending generally normal to the axis of said movable cam and a shorter base leg portion of said notch extending generally parallel to said axis, the length of said tab being greater than the depth of said longer leg portion but less than the depth of said shorter base leg portion, said tab disposed within said notch and cooperative therewith, a base edge of said shorter base leg portion inclined with respect to said end edge at an angle of about 60 degrees, another generally L-shaped notch formed in said movable cam approximately diametrically opposite to said first notch in another end edge of said movable cam, a shorter base leg portion of said another notch extend- 1ng from said another end edge towards but short of said annular cam and inclined with respect to said another end edge at an angle of about 60 degrees, a longer leg portion of said another notch extending from an inner end of said another notch shorter base leg portion generally normal to said axis, a stop pin fixed to said bearing disgxosed within said another notch and cooperative there- Wl References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,468,645 Steinm'ayer Apr. 26, 1949 2,586,429 Hodnette et al Feb. 19, 1952