US1893615A - Nonclosable circuit breaker - Google Patents

Description

Jan. 10, 1933. T. B. EASTBURN NONCLOSABLE CIRCUIT BREAKER Filed June 26, 1951 5 Sheets-Sheet 1 INVENTOR.

T. B. EASTBURN NONCLOSABLE CIRCUIT BREAKER Jan, 10, 1933.

Filed June 26, 1931 5 Sheets-Sheet 2 INVENTOR Jan. 10, 1933. T. B. EASTBURN NONCLOSABLE CIRCUIT BREAKER Filed June 26. 1931 6 Sheets-Sheet 3 INVENTOR Jan. 10, 1933. T. B. EASTBURN NONCLOSABLE CIRCUIT BREAKER Filed June 26. 1931 5 Sheets-Sheet 4 II II""' Ill INVENTOR Jam 10, 1933. T. B. EASTBURN 1,393,515

NONCLOSABLE CIRCUIT BREAKER,

Filed June 26, 1951 5 Sheets-Sheet 5 Patented Jan. 10, 1933 UNITED STATES PATENT OFFICE THOMAS B. EASTBURN, OF BYWOOD, UPPER DARBY, PENNSYLVANIA, ASSIGNOR T I-T-E CIRCUITBRELAKER COMPANY, OF PORATION OF NEW JERSEY PHILADELPHIA, PENNSYLVANIA, A COR- NONCLOSABLE CIRCUIT BREAKER Application filed June 26,

My invention relates to circuit breakers for automatically interrupting electric circuits upon occurrence of abnormal conditions, as overload, low voltage, etc., and more particularly to circuit breakers of the nonclosable type characterized by mechanism preventing the breaker from being held in circuit-closing position so long as abnormal circuit conditions exist.

In accordance with my invention, the operating system of a non-closable circuit breaker, upon circuit-opening movement of the contact system, is biased by spring means, or equivalent, towards a position from which it is movable to reclose the circuit-breaker, and is moved to that position by the spring unless restrained, as manually by an operator.

More specifically and in accordance with some modifications of my invention, the moment of the force exerted by the spring and tending to effect the aforesaid movement of the operating arm is increased by movement of the contact structure toward open circuit position. whereas in another modification, the force, or tension of the spring, is increased by opening movement of the contact structure.

Further in accordance with my invention, the spring assists in opening the circuit breaker, and preferably, irrespective of whether the operating arm is free, or restrained from movement, as by an operator.

My invention resides in circuit-breaker apparatus having the features hereinafter described and claimed. v

For an understanding of my invention and for illustration of several forms thereof, reference is to be had to the accompanying drawings in which:

Fig. 1 is a side elevational view of nonclosable circuit breaker mechanism.

Fig. 2 in side elevation, discloses the circuit breaker structure shown in Fig. 1, in a housing and with an operating arm extend- 1931. Serial No. 547,061.

tional and bottom plan views of another type of non-closable circuit breaker utilizing the invention.

Figs. 6 and 7 disclose additional modifications.

Referring to Fig. 1, the stationary contacts 1 and 2 of the circuit breaker are held in position against the base 3 by the bolts 4 and 5 which pass through the base to receive the clamping nuts 6 and 7 or equivalent. The lower bolt 5 also clamps against the base a U-shaped bracket 8. Pivotally mounted on a pin 9 journalled in the legs of bracket 8, is the arm 10 which carries the movable contact 11 which bridges or connects the stationary contacts 1 and 2. There is also preferably provided, as shown, an arcing contact 12 of suitable material, which is adapted to engage the fixed arcing tip 18 electrically connected to the upper contact 1. A spring, not shown, biases the contact arm 10 to the open circuit position shown in the dotted lines.

On either side of the U shaped bracket 8, extends an arm 14 pivoted on a pin 15 extending through the bracket. The other end of each of the arms 14 pivoted at 16 to a member 17 pivoted on the contact arm at 10a. With the circuit breaker in closed circuit position as shown, the arms 14;, and member 17 between pivots 10a and 16, form an under center toggle. The latch 18 mounted freely on the pivot 9 engages the pin 19 of member 17 to prevent collapse of the toggle and circuit-opening movement of contacts 11.

Upon occurrence of abnormal circuit conditions, for example, overload, the trigger 20 is moved upwardly, rotating counter-clockwise about its pivot 21, to engage the tail 22 of latch 18 and effecting clockwise rotation thereof which releases the pin 19 and permits the circuit breaker to open under the influence of its biasing spring (not shown).

With the construction thus far described, to reclose the breaker the operating arm 23 is moved to its upper position indicated in the dotted line to effect engagement between the nose 24 of a member 2 1a carried by arm 23 and the notch 25 of a latch 26 pivotally mounted on pin 26a ext-ending between the arms 27, which at one end are pivoted on pin 9, and whose other ends are connected by link 28 to the bracket 29 secured as by bolts 30 to the outer end of member 17. When the break er is of the multiple type, the bar 31 clamped between bracket 30 and member 17 may be of sufiicient extent to connect with additional movable contact systems.

7 With the operating arm latched to the movable contact system, as indicated in the dotted line position, the breaker may be closed by moving the operating arm 23 downwardly until the pin 19 of the contact system is engaged by latch 18.

If abnormal circuit conditions obtain when the breaker is closed, and before the operating arm 23 is released, the tripping member 20 in moving upwardly engages the extension 32 of latch 26, disengaging the connection between the operating arm 23 and the movable contact system, substantially simultaneously with release of pin 19 from latch 18, so that the contact arm 10 moves to the dotted line position, even though the handle 23 is retained in the full line position.

the breaker.

If it is desired to trip the breaker manually, the handle 23 of the operating system is moved upwardly causing the lower extension 33 of latching member 26 to engage the tripping member 20 and effect its movement in counterclockwise direction to trip the circuit breaker as previously described. WVhether the tripping is effected automatically or manually, latches 18 and 26 are both actuated one to release the contact system for movement by its spring and the other to disconnect the contact system from its operating system.

With the construction as thus far described,

- in order to re-close the circuit breaker, two

movements are necessary, first an upward movement of arm 23 to effect latching engagement with the contact system, and then a downward movement of member 23 to close Further the operating arm 23 is down when the breaker is closed and remains down upon tripping of the circuit breaker. It is one ofthe objects of the present invention to provide an arrangement in which for circuit breakers of the non-closable type, but a single movement of the open ating arm is necessary to effect re-closing of the breaker and in which the position of the operating system indicates the circuit-controlling position of the circuit breaker.

In accordance with the invention, a spring 34 in Fig. 2 is connected at lbS opposite ends to pins 35 and 36 carried respectively by the arm 23 of the contact-operating system and the links 14 of the contact system. With the circuit breaker in closed position, the axis 00 of the spring is slightly to the right of the pivot 9 as indicated by the short line L, so that the force exerted by the spring on arm 23 tends to open the breaker. The moment of the force, however, is so small, as indicated by the short length of line L, that it is incapable of moving arm 23 to effect tripping of the breaker.

l/Vhen the breaker is tripped either automatically, or by lifting the operating arm 23 manually, the pin 36 at the end of the'spring connected to the movable contact system moves further to the right to the position indicated in dotted lines, which materially increases the moment of the force exerted by the spring on arm 23, the line L indicating the increased moment or length of the effective lever arm.

Assuming that the arm 23 is held manually either because the operator has just reclosed the circuit breaker, or has moved it upwardly to trip the breaker, the force exerted by the spring 34 with pin 36 in its dotted line position, is sufficient to eifect movement of the arm 23 when it is released, to the upper dotted line position, at which the latch 26 by ravity, or by spring means, not shown, re-connects the operating arm to the movable contact system. As the pin 35 at the lower end of the spring moves upwardly, the distance between the aXis of the spring and the pivot 9, or the effective lever arm still further lncreases, which compensates for the decreased length or tension of the spring, and ensures that the force exerted by the spring on arm 23 is sufficient to move it to the upper dotted line position.

In Fig. 2, the circuit breaker mechanism of Fig. 1 is disclosed. within an enclosure 37, which is intended generically toillustrate either a unitary housing for the circuit break er, or a cell of a switchboard of the type disclosed in co-pending application Serial 1T0. 513,812, filed February 6, 1931. Also in Fig. 2 there is specifically shown the coil 38 which is in series with the circuit breaker contacts and which upon abnormally high currents attracts the armature 39 which is connected as by link 40 to the tripping member 20 of the breaker. In the type of breaker specifically illustrated, the armature 39 is connected to the movable element of a retarding device 41 containing a dash pot, sucker disk, or equivalent.

A bracket or supporting member 42 suitably held against base 1, as by the bolts 43, extends adjacent the front panel of enclosure 37 and provides a support for the bell crank lever 44 having one arm 45 provided with a handle 46 disposed eXteriorly of the enclosure and a second arm 47 within the housing and connected as by link 48 to the operating arm 23 of the circuit breaker.

As indicated, with the circuit breaker closed, the arm 45 is substantially vertically disposed. Upon tripping of the breaker the arm 46, when free of, or released from, restraint, assumes the dotted line or substan tially horizontal position, because of the follow-up action of arm 23 induced, as previously described, by spring 34. The position of arm 45, external of the housing, is an index of the circuit controlling position of the circuit breaker. It is therefore possible for an operator, merely by glancing along a switchboard comprised of or having mounted thereon, a number of such units, to immediately and with certainty determine which of the breakers are closed and which are open, even though he may be remote from any or all of the breakers, and substantially independent of the angle from which he views the front of the switchboard.

When the breaker is open, it can be reclosed merely by pushing handle 46 upwardly. To trip the breaker the handle 46 is pulled downwardly a small amount, the handle when released falling still further assuming the horizontal position indicating that the circuit breaker is open.

The circuit breaker mechanism shown in Fig. 3 is similar to that shown in Fig. 1 and the same reference characters have been employed to identify the corresponding elements. The significant difference is the location of the spring 34. In this modification, the spring is attached to pin 49 upon lever 23 which is closer to the pivot 9 of the operating arm, than the pin 35 in the modification .shown in Fig. 1. The other end of the spring is connected to the pin 50 extending from the member 17 adjacent its outer end.

lVith the circuit breaker closed, the spring whose length is indicated by its axis 03, has no tendency to lift the operating arm 23. When, however, the circuit breaker opens the mem ber 17 moves to its dotted line position, stretching the spring as indicated by the increased length of its 021 so that the arm 23, if free, or when released, moves upwardly to the dotted line position. As the distance between the pins 49 and 50 for the dotted line or open circuit positions of member 17 and arm 23, (axial length 022 of the spring) is greater than for their full line or closed circuit position, the arm 23 is held by the spring in the dotted line position when the circuit breaker is open. Differently stated, the spring is under greater tension when members 17 and 23 are in their dotted line positions, than when these members are in their full line position.

In this modification there is little or no change in the effective lever arm, and the action of the spring is dependent substantially solely upon the change of tension.

The modification shown in Fig. 4 is similar to that shown in Fig. 1 and similar reference characters have been used to identify the corresponding elements. In this modification, one end of the spring is connected to pin 49, which as in the modification of Fig. 3, is relatively close to the pivotal axis 9 of arm 23.

' while the other end of the .spring is secured at point 52 to a member 51 extending from the contact supporting arm 10 toward the base 1. The points of support of the ends of the spring connected respectively to the movable contact system and the operating arm are so disposed that with the circuit breaker closed as indicated, the axis a: of the spring passes through the pivotal axis 9 and the force exerted by the spring has therefore no moment tending to lift arm 23.

Vhen the circuit breaker is tripped, the point 52 moves away from the base 1 to the dotted line position so that the spring axis shifts to the right to the position ml. The force exerted by the spring now has sufficient moment to lift the arm 23 to the dotted line position at which the contact system and contact-operating systems are again connected by latch 26. Although the length, or tension of the spring decreases as arm 2-3 moves upwardly, the axis of the spring shifts still further to the right to 002, increasing the moment of the force so that the spring is capable of moving the arm to the dotted line position.

In this modification, similarly to that of Fig. 1, the force exerted by the lift-up spring assists opening of the breaker both when the arm 23 is held, as by an operator, or when it is free.

A non-closable circuit breaker differing in construction from those previously described, is shown in Figs. 5 and 5a. The stationary contacts 53 and 54 suitably secured to the front of the panel 55 are adapted to be bridged by the movable contact 56'carried by the arm 57 which is pivoted on a pin 58 ex tending between the arms of a bracket 59 also held against the front of panel 55. The magnctizable field member 60 embraces the conductor 61 extending from the lower fixed contact 54 to a terminal member 62 connected to a bolt 63 extending to the rear of the panel for connection to one of the line conductors, the other of which is connected to the bolt 63a connected to the upper fixed contact 53.

The member 64 of the contact system is pivotally mounted intermediate its ends on a pin 65 journalled in the outer ends of the bracket 59. One end of the member 64 is pivotally connected by pin 66 to link 67, whose other end is pivoted to pin 68 carried by the contact arm 57. The other arm of member 64 carries a bar or pin 69 which, in the closed circuit position of the breaker, is received by the notched end of a latch 70 loosely mounted on pin 71 extending between the arms of bracket 59. The same end of member 64 also carries a latch 72 which engages a pin or stop 73 carried by the operating arm 74 of the circuit breaker to connect the operating and contact systems of the circuit breaker.

Upon occurrence of overload, the armature 75 is attracted by the field member 60, the extension 76 of the armature system engaging the end 77 of a lever arm 78 pivoted upon pin 71, to effect clockwise rotation of the arm, as viewed in Fig. 5. The finger 79 of arm 78 depresses the latch against the tension of spring 80, releasing the contact system, and permitting it to move to the open circuit or dotted line position by spring or other means not shown.

Substantially simultaneously the tripping member 81, which may be integral with arm 78, is depressed, which, by engagement with the end 82 of latch 72, releases the contact system from the arm 74 of the contact-operating system.

With the circuit breaker in closed circuit position tripping may be effected manually by moving arm 74 in counter-clockwise direction by a small amount. By this movement, the roller 83 which is mounted on the lower end of an arm 84, pivoted on the operating arm 74, efiects clockwise rotation of the tripping member 7 8, which as previously described operates the latches 70 and 72 to permit the breaker to open, the operating arm 7 4 remaining in the full line position in the absence or" elements subsequently described.

With the construction thus far described, the contact system moves to the dotted line position upon tripping of the breaker, either automatically or manually, the operating arm and associated parts remaining in full line position.

To obtain an arrangement in which the circuit breaker may be re-closed by a single movement of the operating handle, and which has the further advantage that the operating handle indicates the circuit breaker position, while retaining the. non-closable feature, manual trip by reverse movement of the operating member, etc., additional elements now described are added- A second toggle is formed by the links 85 and 86 whose common pivot is at 87 and whose other ends are pivoted to pin 68, carried by the arm 57, and pin 65 in the bracket 59.- Vith the circuit breaker in closed position, the arms 85 and 86 form an over center toggle. On opposite ends of the pin 87 are mounted the arms 88, to the free end of each of which is secured one end of a spring 89 whose other end is suitably attached, as by a plate 90 to a pin 91 extending from the operating arm 74. With the breaker in the closed circuit position, the axis of the spring substantially coincides with the center line of thepins 87, 65 and 91, and consequently the force exerted by the spring has little or inappreci able tendency to effect movement of the operating arm.

When however, the circuit breaker is tripped, the pin 87 moves to the dotted line position, shifting the axis of the spring substantially to the right of the pin 65 on which the arm 74 is pivoted. By virtue of this movement, the force exerted by the spring counter-clockwise movement of arm 74, and

if the arm is free, the arm 74 moves up to the dotted line position, the latch 72 re-engaging the stop 73 to reconnect the contact and contact-operating system. It is to be noted that as arm 74 swings upwardly the moment of the force exerted by the spring increases which compensates for the decreased length of the spring and insures that the spring action is sufiicient to carry the arm 74 into latching position.

If the circuit breaker trips automatically during attempted manual closure, the contact structure moves to the dotted line position shifting the axis of spring as previously described. VVhen arm 74 is subsequently released, the spring 89 moves it to the dotted line position. If the arm 74 is restrained during manual tripping, the axis of the spring is shifted as before described so that arm 74 moves to open position as soon as released by the operator.

By provision or". the spring, the contact and operating systems are automatically re-connected after the tripping of the circuit breaker, and but a single movement of arm 74 is necessary to re-close the breaker. The arm 74 may be connected, as by link 48, to an operating arrangement similar to that disclosed in Fig. 2, in which the handle extends exteriorly of a casing or enclosure. By the action of spring 89, the position of the handle when free, indicates the circuit-controlling positions of the circuit breaker. I

A modification of the circuit breaker of Fig. 5 is shown in Fig. 6. As in the previous types described, this circuit breaker may be arranged to be operated by a link 48. The latches 70 and 72 are utilized as in the prior modifications and in this construct-ion the latch 72 is provided with an extension 92 which at the end of the closing motion comes into contact with plunger 93 supported on an arm of the tripping member 95. The spring 94 which biases the plunger 93 to the right, tends to rotate the latch 72 in counterclockwise direction, but is held in position by friction until the pressure of closing is relieved. Shortly after extension 92 engages plunger 93, the latch 7 0 receives the roller 69, and shortly thereafter the stop 96 of the arm 64 abuts against bracket 59.

When the link 48 is released after closing of the breaker, the arm 97 is drawn down by spring 98 or equivalent, as a weight, until the stop pin 99 engages arm 64. This reverse movement releases the pressure between latch 72 and roller 73 and allows spring 94 to move the latch clear of its roller 73.

The arm 7 4 i new tree to move down, and this motion may be utilized to trip the circuit breaker manually; specifically, downward movement of arm 74 causes its extension 100 to engage lug 101 of the tripping member 95, moving it to the left, and thereby effecting downward movement of the lip 79, to release latch 70. The arm 64 thereupon moves counter-clockwise to open the breaker. When link 48 is released, the spring or weights 98 effect a counter-clockwise rotation of the lever 74 until the stop 73 carried thereby is re-engaged by the latch 7 2 of the contact system.

As in previous modifications the arm 74 and any handle connected to link 48, when unrestrained, indicate the circuit condition of the breaker; specifically, the arm 7 4 when not manually restrained is up when the breaker is open and down when the breaker is closed. A single, downward motion of arm 74 closes the circuit breaker since when the breaker opens for any reason, the arm is moved by the springs 98 to the relatching position with arm 64. Subsequent to release of the operating handle, or link 48, the circuit breaker may be tripped manually by further downward movement of arm 74, or link 48.

A further modification is disclosed in Fig. 7. The arm 64 of the contact system carries at its outer end a pin 102 which is adapted to be caught by the latch 103 pivoted at 104 on arm 7 4 of the operating system. The end 105 of latch 103 lies close to and is engageable by the tripping member 81 so that upon downward movement of the latter, the latch is rotated counter-clockwise to disengage pin 102. The operating arm 74 is held down against the bracket 59 by the latch 110 which engages pin 111 secured to arm 74. In effect, the two latches are in series when the circuit breaker is closed.

The tripping of this circuit breaker may be accomplished manually by lifting the link 48 which eifects rotation of member 107 counter-clockwise about the pin 106 to eifect engagement between the lug 109 of member 107 and the end or tail 105 of latch 103.

The springs or weights 98, as in the modification of Fig. 6, move the arm 74 upwardly to effect re-engagement between latch 103 and pin 102 carried by the arm 64 of the contact system.

To reclose the breaker the link 48 is moved downwardly and with the closing force being transmitted from the member 107 to arm 7 4 through the lug 108.

The several types of circuit breakers are particularly suited for use in multiphase circuits, particularly multiphase lighting circuits. A separate breaker is included in each phase so that upon overload in one phase, only the circuit of that phase is interrupted leaving the lights, for example, in the other phases in continued operation.

While I have illustrated several preferred forms of my invention, it will be understood that my invention is not limited thereto but corresponds in scope to the appended claims.

What I claim is:

1. A non-closable circuit breaker comprising a movable contact system, an operating system, means disengageably connecting said systems, and spring means connecting said systems and so arranged that it is effective upon movement of said contact system toward open circuit position to bias said operating system for movement efi'ecting connection between said systems by said disengageable connecting means.

2. A non-closable circuit breaker comprising a movable contact system, an operatin system, means disen ageably connecting said systems, spring means connecting said systems and so arranged that it is effective upon movement of said contact system toward open circuit position to bias said operating system for movement effecting connection between said systems by said disenga-geable connecting means, an enclosure for said circuit breaker, and a member included in said operating system and extending eX- teriorly of said housing to indicate the circuit-controlling position of the contact system.

3. A non-closable circuit breaker comprising a movable contact system, an operating system, latching means restraining said contact system in closed circuit position and disengageably connecting said systems,

means responsive to abnormal circuit conditions for actuating said latching means, means responsive to movement of structure included in said operating system in a predetermined direction for actuating said latching means, and spring means connecting said systems and so disposed that it is effective, upon movement of said contact system subsequent to actuation of said latching means by either of said responsive means, to move said operating system to effect reconnection with said contact system.

4. A non-closable circuit breaker comprising a movable contact system, an operating system, an enclosure for said circuit breaker, a member included in said operating system and extending eXt-eriorly of said housing for manual operation of the circuit-breaker, latching means restraining said contact system in closed circuit position and disengageably connecting said systems, means responsive to abnormal circuit conditions for actua-ting said latching means, means responsive to movement of said member in a predetermined direction for actuating said latching means, and spring means so disposed and arranged that it is effective, upon movement of said contact system subsequent to actuation of said latching means by either of said responsive means, to move said operating system to effect re-oonnection with said contact system and to move said member to a position indicating open-circuit condition of the circuit-breaker. 5. A non-closable circuit breaker comprising a movable contact system, an operating system, latching means disengageably connecting said systems, means for actuating said latching means, and spring means connected between such points in said systems that when the circuit-breaker is closed the force exerted by the spring has no substantial moment tending to efiect movement of said operating system but whose relative positions are so changed upon movement of the contact system toward open position that the moment of the force is increased to efiect movement of said operating system to reconnect said systems by said latching means.

6. A non-closable circuit breaker comprising'a movable contact system including a pivoted member, an operating system including a pivoted member, latching means disengageably connecting said systems, means for actuating said latching means, and spring means connecting said members whose axis for closed position of the circuit breaker passes at or adjacent the pivotal axis of said second member and upon opening movement of said contact system shifts more remote from said pivotal axis to effect movement of said member reconnecting said systems by said latching means.

7. A non-closable circuit breaker comprising a movable contact system including a pivoted member, an operating system includ ing a movable member, means responsive to abnormal circuit conditions, latching means restraining said contact system in closed circuit position, latching means disengageably connecting said systems, mechanism actuatable by said responsive means or movement of said movable member to release both of said latching means, and spring means connecting said systems so disposed and arranged as to be effective upon movement of said Contact system to open circuit position to move said operating system to effect reconnection or" said systems by said second latching means.

8. A non-closable circuit-breaker comprising a movable contact system including a pivoted member, an operating system including a movable member, means responsive to abnormal circuit conditions, latching means restraining said contact system in closed circuit position, latching means disengageably connecting said systems, mechanism actuatable by said responsive means or movement of said movable member to release both of said latching means, and spring means connecting said systems, the moment of whose force is increased upon movement of said contact s stem to 0 en circuit 'osition to move said operating system to effect reconnection of said systems by said second latching means.

9. A non-closable circuit breaker comprising a movable contact system including a pivoted member, an operating system including a. movable member, means responsive to abnormal circuit conditions, latching means restraining said contact system in closed circuit position, latching means disengageably connecting said systems, mechanism actuatable by said responsive means or movement of said movable member to release both of said latching means, and spring means so disposed and arranged that its tension is increased by movement of said contact system to open circuit position and adapted to move said operating system to effect reconnection of said systems by said second latching means.

10. A non-closable circuit breaker comprising a movable contact system, a contact-operating system, latching means restraining said contact system in closed circuit position, latching means disengageably connecting said systems, spring means connecting said systems, and a member included in said operating system movable in one direction to actuate both of said latching means and movable in a single direction to eii'ect re-closing of the circuit breaker by movement of said contact system for re-engagement of said first latching means, said spring means upon tripping of the circuit breaker effecting re-connection of said systems by said second latching means and movement of said member to position indicating open-circuit condition of the circuit-breaker.

11. In a circuit controlling device, two.

levers concentrically mounted on a stationary support, each movable between stop structure and the other lever, and spring means connected between one of said levers and to a link system operated by the other lever, said spring cooperating with said levers and said links to hold said levers together at one limit of their movement and to exert no holding force when said levers are together at another limit of their movement. 7

12'. A circuit breaker'comprising a contact system, an operating system therefor including a control lever, latching means for re straining said contact system in closed circuit position and for disengageably connecting said systems, means responsive to circuit conditions for releasing said latching means, means for insuring that the position of said control lever, when manually unrestrained, indicates the circuit position of said contact system, and means operative'when said contact system is in closed circuit position to effect actuation of said latching means by movement of said control lever. r

13. An enclosed circuit breaker comprising enclosing structure, a contact system, an operating system therefor including acontrol lever extending externally of said enclosing structure, latching means restraining said contact system in closed circuit position and for disengageably connecting said systems, means responsive to circuit conditions for releasing said latching means, and means for ensuring that the position of said control lever, when unrestrained, indicates exteriorly of said enclosure, the circuit controlling position of said contact system.

14. A circuit breaker comprising a contact system, an operating system, latching means for restraining said contact system in closed circuit position and for disengageably connecting said systems, an arm movable in one direction to effect closing of said circuit breaker, and means for tripping said circuit breaker when said arm is again moved in said one direction.

15. A non-closable circuit breaker comprising a contact system, an operating system therefor, latching means disengageably connecting said systems, a control member included in said operating system and mechanically held in closed circuit position solely by said latching means, electro-responsive means for releasing said latching means to elfect movement 01 said contact system to open circuit position, and spring means connecting said systems arranged to move said control member to open circuit position upon opening movement of said contact system and to efiect relatching of said systems by said latching means.

16. A non-closable circuit breaker C01 prising a movable contact system, an operating system, latching means disengageably connecting said systems, means for actuating said latching means, spring means connected between such points in said systems that when the circuit-breaker is closed the force exerted by the spring has no substantial moment tending to effect movement of 0 said operating system but Whose relative positions are so changed upon movement of the contact system toward open position that the moment of the force is increased to effect movement of said operating system to reconnect said systems by said latching means,

and a lever included in said operating system moved by said spring means in one direction to open-circuit indicating position and manually operable in reverse direction to closed-circuit indicating position during resetting of the breaker.

THOMAS B. EASTBURN.

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