US2301765A - System of control for high voltage circuit interrupters - Google Patents

Description

Nov. 10, 1942. I v RQWILKHQS A2,391,765

SYSTEM OF CONTROL FOR HIGH VOLTAGE CIRCUIT INTERRUPTERS i IN VEN TLOR.

Nv. 10, 1942. R.' wlLKlNs 2,301,765

SYSTEM OF CONTROL FOR HIGH VOLTAGE CIRCUIT INTERRUETERS Filed Jan. 10, 1941 2 Sheets-Sheet 2 Patented Nov. 10, 1942 SYSTEM OF CONTROL FOR HIGH VOLTAGE CIRCUIT INTERRUPTERS Roy Wilkins, Hamburg, Calif.

Application January 10, 1941, Serial No, 373,940

12 Claims.

The present invention relates to a system of control for circuit interrupters, and more particularly circuit interrupters of the so-called oilless and/or minimum-oil types in which the contacts are separated in an arc interrupting medium carried by a container insulated from ground and operating in the high voltage Zone of a power transmission line and is a continuation in part of my copending application Serial No. 287,968, filed August 2, 1939.

One of the objects of the invention is to provide a new and novel control for circuit breakers of the type described in which the overload tripping means of the circuit breaker is insulated from ground in a new and novel manner.

Another object of the invention is to provide a new and improved high speed overload tripping mechanism for a circuit breaker operating on a high potential line which may be operated in a safe and eflicient manner.

Another object of the invention is to provide a trip free mechanism for a circuit breaker of the above type in which the number and mass of the parts movable upon overload to interrupt the circuit are reduced to a minimum.

Another object of the invention is to provide an overload tripping mechanism for a high potential circuit breaker of the type having a conventional opening and closing mechanism of the spring, solenoid or motor operated type that will operate, in the event of an overload, to permit an opening of the circuit breaker independently of its operating mechanism.

Another object of the invention is to provide a safe and efficient operating mechanism for a high potential circuit breaker that may be lccated in a Zone of high potential and which can be controlled by mechanical and electro-responsive means operating in a zone of low potential.

At the present time the practice in the con- L' moderately high voltage circuits, it has met with some objection upon the extremely high voltages, such as are now being used in electric power transmission service. This is due to the diniculty encountered in interrupting circuits of this latter class, particularly on short circuit, as fr under these conditions the arc drawn between the separating contacts generates gas and often creates an excessive pressure which in many instances fractures the tank and results in a release of the oil contained therein and thus presente a serious re hazard. A further objection is in the fact that circuit breakers of this type require large and expensive insulating` brsliings.

To overcome the above objections, the tendency now is to mount the current interrupting contacts of the circuit breaker in a relativeli7 small insulated arc extinguishing chamber containing only a sufficient amount of oil, water and/or other arc extinguishing medium to extinguish the arc. This is at the present time being accomplished by conning the oil and/or other arc extinguishing medium in an insulating bushing within which the separable contacts of the circuit breaker are operatively mounted, the insulating chamber thus formed being itself supported upon and insulated from ground by a further insulating means, as for example, a suitable supporting bushing. With this construction, the problem of reducing the amount oi oil and/or other arc extinguishing medium required is effectively solved, but due to the fact that the circuit interrupting contacts must of necessity be operated through a mechanical connection controlled by apparatus located and operating at ground potential, there still remains the problem of effectively operating the circuit breaker in a safe and efficient manner.

It is, therefore, a further and additional object of the present invention to provide a new and novel operating mechanism and control for the current interrupting contacts of a high potential circuit breaker of the so-called minimumoil or oilless types which will solve the insulating problem and at the same time reduce the number of operating parts to the end that the eiiciency and speed of operation oi the circuit breaker upon overload will be greatly increased.

Other objects and advantages of the invention will be in part evident to those skilled in the art and in part pointed out hereinafter in connection with the accompanying drawings, wherein there is shown by way of illustration and not of limitation a preferred embodiment thereof.

In the drawings- Figure 1 is a view in elevation of a circuit breaker of the type contemplated by this invention having parts broken away to show details of construction and having a control circuit diagrammatically associated therewith,

Figure 2 is a fragmentary side elevationcf the upper portion of the circuit breaker showing the parts in diiierent positions,

Figure 3 is a View similar to Figure 2 ing the parts in still another position,

Figure 4 is a diagrammatic view showing the circuits by means of Which the spring releasing latches are controlled, and

Figure 5 is a side elevation of a spring type of operating mechanism suitable 'for use with this invention.

showe proceeding w ith a n for vention, it is believed that d ig thereor will be facilitated by makinc reference to two examples of the prior illustrating previously proposed solutions to the insulation aspect of the present invention. One of the earliest attempts to this end is illustrated in Patent No. 975,426, issued November l5, 1910, to F. W. Harris. In this disclosure the inventor mounted the current responsive overload tripping relay of the circuit breaker upon a suitable insulating support at a point closely adjacent the high potential zone of the transmission line remote from the circuit breaker and then mechanically connected it through a relatively long insulating rod or bar to the tripping mechanism of the circuit breaker operating at ground potential While this arrangement proved satisfactory for the voltages then in use, it still required the relatively large capacity oil containing tank and the expensive bushings through which the transmission line was connected to the circuit breaker contacts. A further objection to the arrangement of this disclosure resides in the fact that all of the operating mechanism of the circuit breaker is required to move upon each opening and closing of the circuit breaker contacts and this, together with increased mass introduced into the mechanical tripping mechanism by the insertion of the long insulating rod used to connect the overload tripping relay, located in the high potential zone, with the mechanical actuating mechanism operating at ground potential, introduced such an additional mass in the movable parts oi" the tripping control of the circuit breaker that its action upon overload is too slow for present day needs.

A more recent attempt at a solution to the insulating problem contemplated by the present invention is illustrated by the Patent No. 2.057,472, issued October 13, 1936, to E. R. Bonds. In this latter disclosure the inventor has appreciated the difficulties encountered in insulating the overload tripping relay located in a high potential zone from the control circuit and mechanical tripping mechanism of the circuit breaker which is normally operated from a lov.1 voltage source at ground potential. 'The solution here presented still requires the large capacity oil tank and the expensive bushings through which the line conductors are connected to the circuit breaker contacts, but it has eliminated the mechanical connection between the relay and the circuit breaker operating mechanism provided by the long and heavyv insulating rod or bar previ- Ously required. In this disclosure the circuit breaker tripping mechanism located and operating at ground potential from a low voltage source of power is responsive to a photo-electric cell circuit in which a beam oi light is directed upon a photo-electric cell by means of a mirror or other reecting surface, the position of which is controlled by an overload relay that is responsive to the current flowing in the line and through the circuit breaker contacts. While this arrangement eiectively insulates the control circuit of the circuit breaker from the high potential line, it is open to the objection that the relay and the photo-electric cell circuit require constant supervision and frequent adjustments and, therefore, it is not as reliable as it might otherwise be.

In accordance with the present invention the circuit interrupting contacts of the circuit breaknism.

er are mounted within a relatively small arc extinguishing chamber or pot that is elevated and insulated from ground by a suitable insulating support. This form of construction, as is clearly understood in the art, avoids the necessity for the large capacity oil tank in which the oil serves the dual purpose cf extinguishing the arc upon a circuit interruption and as an insulator between the high tension conductors and contacts of the circuit breaker and ground. In circuit breakers of this type the relative movement between the circuit interrupting contacts is controlled by an operating mechanism which is located below the circuit breaker and operated at ground potential, the operating mechanism being connected with the moving contact elements of the circuit breaker' through a rotatable column of insulators. In the prior art arrangements of this type, the automatic overload tripping devices which are associated with the circuit breaker have been located adjacent the operating mechanism at ground potential and as a resu t, when the circuit breaker is required to open, as upon overload, a tripping of the circuit breaker requires that the connecting column ci insulators must also move, and as a result the action o the circuit breaker in opening upon overload is greatly retarded, due to the inertia or mass of this connecting column of insulators. To overcome this objection the present invention provides a trip free operating mechanism and a control therefor which will permit an opening of the circuit breaker contacts free of the connection with the operating mechanism.

Reference is now made to Figures l, 2 and 3 of the drawings for a detailed description of the invention. As here shown, the numeral lil designates a hollow cylindrical insulator structure which is adapted to contain a quantity of oil and/or other arc extinguishing huid il in which the separable contacts of the circuit breaker are adapted to be immersed. At the lower end of the insulator structure there is an end closure assembly I2 which supports a main stationary Contact i3 of the circuit breaker. rl`^his end closure assembly l2 is secured upon a suitable cap E4 which is carried by a second cylindrical insulator structure I5 that is mounted upon a foundation or base forming member l5. The base forming member lE, in addition to providing a support for the insulator structure E 5 and the circuit breaker elements carried thereby, may also serve as a support and/or a housing ior any desired form of circuit breaker operating mecha- At the top of the insulator structure l0 there is a Contact supporting member S7 which carries a stationary brush-type contact l through which a main moving contact 9 of the circuit breaker is adapted to extend. rI'he moving contact I9 is here shown as confined to a vertical path of movement in alignment with the stationary contact i3 by means of a guide 20 that extends downwardly into the cylindrical insulator structure i6. For the purpose of connecting the circuit breaker contacts i3 and le into a high potential transmission circuit, the end closure assembly l2 is provided with a terminal 2l and the Contact supporting member Il is provided with a terminal 22.

As a means for controlling the normal operating movements oi the movable co ct i9, the circuit breaker here illustrated alsU includes a vertically disposed series of insulators 23 which form a non-conducting mechanical power transmitting means for imparting an operating movement to the movable contact I9 of the circuit breaker. At its lower end, the series of insulators 23 terminate as a shaft 24 which is adapted to be driven by any suitable energy providing mechanism, one form of which will be described hereinafter. Intermediate its ends, the series of insulators 23 is guided and supported by a bearing forming member 25 and at its upper end it connects with a shaft 26 that is rotatably journaled upon the contact supporting member While the present invention contemplates an operating mechanism for controlling the circuit opening and closing movements of the circuit interrupter which is located and operable in a zone of high potential, it is to be understood that the character of this operating mechanism may also take many forms, the only limitation in this respect being that it have electrically controlled means for rendering it operative, independently of the normally operating mechanism, to open the high potential circuit in the event of an overload. For purposes of illustration, the moving contact I9 of the circuit interrupter is shown as suspended upon a tension spring 21 that is adapted to bias the contact |9 into its open circuit position, as illustrated in Figure 1 of the drawings. The spring 2'| is here shown as supported from a cover forming member 28 which is carried by the contact supporting member II by means of a projecting bracket 29. Connected to the moving contact member I9 through a link 3U there is a lever arm 3| that is pivoted upon a support 32. Pivotally mounted at the end of the bracket 29 there is a second lever arm 33, between the free end of which and a further bracket 34 carried by the cover 28 there is disposed two toggle forming links 35 and 36. As shown, the link 36 is adapted, when the toggle is in an extended position, to engage an abutment 31 that serves to retain the toggle so formed in its extended position. The mechanism also contemplates a second toggle arrangement which is disposed between the free end of the pivotally mounted lever 33 and the lever arm 3|. This second toggle arrangement comprises links 38 and 39. As shown, the toggle arrangement thus formed by the links 38 and 39 is adapted to be controlled by a connecting link 40 that extends from the connected ends of the links 38 and 39 to a crank arm 4| mounted upon the end of the shaft 26 previously referred to as operatively connected to the vertically disposed series of insulators 23 which form the non-conducting mechanical power transmitting means that serves to operate the circuit breaker, the link 49 being connected to the end of the crank 4| by means of a swivel connection 42. With this arrangement it will be seen that when the toggle formed by the links 35 and 36 is in its extended position, the movable contact member |9 may be moved between its circuit open and its circuit closed positions by a collapse and extension of the toggle formed by the links 38 and 39 through rotation of the shaft 26. It will be understood that when the toggle mechanism formed by thev ings. This latter operation of the moving contact I9 is contemplated only in the event of an abnormal or overload condition upon the high potential circuit in which the circuit interrupter is connected and to this end the invention contemplates a means by which the toggle formed by the links 35 and 36 may be collapsed under these conditions. In the drawings this means is illustrated as an electro-magnetically responsive tripping device 43 which is designed and adapted to respond to an electrical impulse inductively transmitted thereto.

From the above it will be seen that when the toggle mechanism formed by the links I35 and 36 is in its extended position, as illustrated in Figure l of the drawings, the toggle mechanism formed by the links 38 and 39 may be collapsed and extended by a rotation of the crank 4i. This will cause the pivotally mounted lever arm 3| to oscillate in such a manner about its pivot 32 as to move the moving contact member I9 between its open and closed circuit forming positions with respect to the stationary contact I3 as the toggle mechanism formed by the links 38 and 39 is respectively collapsed and extended. On the other hand, as is clearly illustrated in Figure 2 of the drawings, should the toggle mechanism formed by the links 35 and 36 be collapsed, it will be apparent that rotation of the crank arm 4I upon the shaft 26 will become inoperative to retain the moving contact I9 in its closed circuit forming position and/or to impart any operating movements thereto. This is due to the fact that the toggle formed by the links 38 and 39 will then have no fixed support against which it can exert a downward force upon the pivotally mounted lever arm 3| in opposition to the tension spring 2'I. Therefore, under these circumstances, the spring 2'I will operate to hold the moving contact |9 in its open circuit position.

In practice, circuit interrupters of the high potential type, such as are contemplated by the present invention, are operated by an electric motor and/or a spring operating mechanism which is responsive to a low voltage control circuit that is maintained independently of the high potential transmission line in which the circuit interrupter is connected. For convenience, and particularly in outlying districts, these control circuits may be energized from a direct current source, such as a storage battery. In order to control the circuit interrupter in response to conditions on the high potential circuit with such a low voltage control circuit, and particularly to effect an opening of the interrupter in the event of an overload, it is customary to include a circuit control relay for this circuit which will become operative in the event of an overload upon the high potential circuit. Such a relay, designated by the numeral 44 is shown diagrammatically in Figure 1 of the drawings as having its operating coil connected to the high potential circuit through an insulating transformer 45 by means of conductors 46 and 4T. As shown, the contacts of the overload relay 44 are associated with a low voltage control circuit which is represented by conductors 48 and 49. These conductors 48 and 49 preferably provide a low voltage direct current source of supply which is connected with a battery or other suitable source of electric current. In practice. the low voltage circuit indicated by the conductors 48 and 49 will, in addition to its intended function, as contemplated by the present invention, also serve as a source of electric power for operating the usual electro-magnetic devices, such as relays, tripping coils and the like, that are customarily provided with all high potential automatic reclosing circuit interrupters. In addition to this low voltage source of direct current for supplying the various electro-magnetic devices that control the circuit interrupter operating mechanism, the invention also contemplates a source of mechanical energy for operating the circuit interrupter mechanism. One type of spring operated mechanical energy supplying means which is suitable for use with a circuit interrupter constructed as illustrated in the accompanying drawings constitutes the subject matter of Patent No. 2,182,239, issued December 5, 1939, to August C. Schwager. For the purpose of this application, it may be briey stated that this prior disclosure contemplates an energy storing spring which is adapted to be controlled by suitably arranged magnetically controlled latching means that in turn are adapted to be controlled by a low voltage control circuit similar to that provided by the conductors 48 and 49 referred to above.

While the present invention is not limited to any particular type of mechanical energy supplying means for operating the present circuit interrupter, the diagrammatic control circuit illustrated in Figure 1 of the drawings is shown as including an electro-magnetic means 50 that is adapted when energized to release a latch I that cooperates with a latching plate 52 which is driven by an energy storing spring, as will hereinafter appear. The showing of the electro-magnetic means 5, together with the latch 5| and the latchincr plate 52, is here made in order to illustrate the manner in which the present invention is adapted to cooperate with a mechanical energy supplying means which may be used for opening and closing the circuit interrupter under normal operating conditions. It is, therefore, to be understood that a showing of these devices is purely incidental and that the mechanical energy supplying means which connects with the shaft 24 may be controlled by other devices that may or may not be responsive to the control circuit contemplated by the present invention. In other words, while the idea of controlling the mechanical energy supplying means by devices similar to those here illustrated may not of itself be novel, it is considered that the controlling of such devices simultaneously with and/ or in conjunction with the control of an automatic trip-free device with a control mechanism operating in a zone of high potential, as provided for by the electromagnetic means 43, is novel.

Reference is now made to Figures 4 and 5 of the drawings for the purpose of pointing out in more detail the manner in which a circuit breaker operating mechanism of the spring type, such as is illustrated in the aforementioned Patent No. 2,1;32239, may be modified in an obvious manner used with a circuit breaker constructed in accordance with the present invention. As in the case of this earlier disclosure, the operating spring, here designated by the numeral 65, is adapted to be controlled in its operation by two latches which, when successively operated, permit the spring to impart a series of successive angular movements to the circuit breaker operating shaft. In the present arrangement, the latching disc E2 is shown as connected directly to the circuit breaker operating shaft 24 rather than through a universal link connection, as shown in this prior patent. Upon referring to Figure 5 of the drawings, and as is more clearly pointed out asonvcs in the aforesaid Letters Patent, the operating spring 65 is of the torsional type and is composed of several independent springs which are connected together in end to end relation by connesting plates 61. At its upper end the operating spring 66 thus formed is connected to a plate G3 that is keyed upon a vertically extending shaft G9 which, in the present instance, is shown as connected directly to the circuit breaker operating shaft 24. The shaft B9 is also here shown as carrying the latching plate 52 with which the latch 5i, shown in Figure 1 of the drawings, is adapted to cooperate. In addition to the latch 5l, the latching plate 52 is also associated with a second latch l. These latches 5| and IU are arranged in oppositely disposed relation with respect to the latching plate 52 where they are adapted to cooperate and permit the spring 65 to impart a series of successive operating movements to the circuit breaker operating shaft 24, as will hereinafter appear. At its lower end the operating spring 66 is connected to a plate 'll that is freely rotatable about the axis of the shaft 65 and which is connected to a shaft 12 that is adapted to be rotated by an electric motor 73 through the medium of a reduction gearing 14. With this arrangement it will be seen that when the motor 73 is energized, it will drive the shaft 'I2 and thus turn the lower end of the operating spring 65 so as to store energy therein. At the same time it will be understood that when the latches 5i and T0 successively operate, the latching plate 52 will be permitted in the present instance to turn through an angle of and thus permit the shaft B9 to turn and thus absorb energy from the operating spring 66. The operating spring 66 is also shown as provided with a differential mechanism by means of which it may be automatically maintained in a predetermined wound condition. This differential device is fully described and claimed in the aforementioned prior art patent and, therefore, it should be suliicient to here point out that this means includes a limit switch 'l5 that is adapted to control the circuit of the motor i3. The limit switch 15 is responsive to an operating shaft 16 that is axially movable by means of a worm 'il which is associated with a small gear 13 that is driven by a larger gear T9 carried by the plate 63 at the upper or energy supplying end of the operating spring ES. At its lower end the shaft T5 slidably carries a second small gear E!! which is adapted to be driven by a larger gear 8| that is connected to the lower end of the operating spring B5. In this manner, as is clearly pointed out in said prior patent, the shaft I6 is adapted to be moved axially in response to any relative radial displacement between the ends of the operating spring 66. In this figure of the drawings, the device is also shown as employing a loading means, such as is described in the aforementioned prior art patent. This loading means, designated by the numeral 82, is fully described in said prior patent and serves to reduce the impact with which the latching abutment carried by the latching plate 52 will strike the latches 5l and l!! when it moves into latched relation therewith.

From the above it vvill be readily seen that the problem of insulating the mechanical operating means, shown in Figure 5 of the drawings, from the circuit interrupter operating mechanism, as represented by the toggle mechanisms which are located in the zone of high potential, is taken care of by the insulated mechanical connection provided by the series of insulators 23. However, since the present invention contemplates a new arrangement in which an overload tripping mechanism is associated with an operating mechanism disposed in a Zone of high potential, as distinguished from prior art arrangements wherein the overload tripping mechanism is located at ground potential, it has been found necessary to devise a further means for establishing a controlling circuit between this overload tripping mechanism and the source or operating current provided by the low voltage conductors 48 and This result is obtained, in accordance with the present invention, by connecting the electro-magnetically responsive tripping device i3 with the low voltage direct current control circuit conductors d and 4S through an inductively coupled impulse transmitting circuit. In Figure l of the drawings this circuit is illustrated as comprising conductors 53 and 54 which connect with a secondary winding 55 of an insulating transformer 55, and conductors l and 5S which connect a primary winding 59 of the insulating transformer 5S to the control circuit conductors :i3 and dii. In order to render the control circuit thus formed responsive to load conditions upon the high potential circuit which extends through the circuit interrupter between terminals 2i and 22, the overload relay ifi is provided with a contact iii) that is adapted to close and open the primary side of this inductive circuit in the event oi an overload on the high potential circuit. In addition to the contact iii the overload relay d4 is also shown as having a second contact 6i that is adapted to simultaneously establish a circuit from the control circuit conductors #it and t9 through conductors 62 and 53 which form a control circuit for the electro-magnetic means 5) that, as has been hereinbefore stated, serves to control the mechanical circuit interrupter operating mechanism.

With a circuit such as has been described above formed between the electro-magnetic tripping device 43 and the direct current control circuit conductors :it and d, it will be readily understood that when the contact 69 of the overload relay 44 is moved into its closed circuit position, a current impulse will be transmitted through the conductors 5I and 53 to the primary winding 59 of the insulating transformer 55 and as a result this impulse will be inductively transmitted to 'the secondary winding 55 and through the conductors 53 and 55 to the electro-magnetic tripping device This current impulse will cause the electro-magnetic device 43 to operate and collapse the trip-free toggle mechanism formed by the links 35 and 35 and thus permit the spring 27 to move the moving contact I9 and the operating mechanism of the circuit interrupter'into the positions illustrated in Figure 2 of the drawings. With such an inductively coupled control circuit between the electro-magnetic device i3 and the control circuit conductors 48 and #le it is also conceivable that the electrical impulse might be produced in a reverse manner by an opening of the circuit through the contact ii of the overload relay M, and as a further variation in this respect, it is also conceivable that the overload relay 'it may be of such a character as to operate its circuit controlling contact 60 with a vibratory action which, as is well understood in the art, would produce a pulsating direct current through the inductively coupled circuit by means of which the electromagnetic device 43 can be operated. Since the secondary portion of the inductive control circuit, as represented by the conductors 53 and 54 and the secondary of the insulating transformer 56, must necessarily extend from a zone of high potential, the insulating transformer 56 is shown as mounted within an insulating oil containing bushing 6d which may be mounted upon any suitable support 55.

'Upon referring to 'Figure 4 of the drawings, it will be seen that the spring retaining latch 'iii is adapted to be operated into its latch plate releasing position by an electro-magnetic means t3 which is connected through conductors 84 and to the low voltage control circuit conductors 48 and 49. The circuit formed by the conductor 85 also includes a manually operable push-button switch 85 by means of which the circuit of the electro-magnetic means et may be established to effect a closing oi the circuit breaker by releasing the latch Iii. It will also be understood that in addition to the manually operated push-button switch Sii, this circuit may be provided with an electro-magnetically operating switch which is responsive to an automatic reclosing circuit, as is taught by the aforesaid patent to August C. Schwager or in any other manner well understood in this art.

The operation of the circuit interruptor chosen for the purpose of illustrating the present invention should be clearly understood from the above and, therefore, it is considered that no detailed description thereof should be necessary, except to state that in practice the mechanism that provides the operating energy which is applied to the shaft 24 is of such a character as to turn the shaft 24 through a sucient operating angie upon each opening of the circuit interruptor contacts, and through a similar angle upon each closing of the circuit interrupter contacts. In other words, with the parts in the positions shown in Figure l, the impartation of such an angular motion to the power transmitting connection formed by the series oi insulators 23 will cause the crank arm di carried by the shaft 2t to move from its right-hand position, as illustrated, to the position illustrated in Figure 3. Therefore, in the event of such a motion of the crank arm 1H, assuming that conditions on the high potential circuit are normal and that the toggle mechanism formed by the links 35 and 35 is in its eX- tended position as illustrated, the connecting link di! will operate to collapse the toggle mechanism formed by the links 38 and 35 and permit the lever arm 3l to move upwardly under the influence of the tension spring 2j. This wiil also carry the moving Contact i9 oi' the circuit interrupter out of circuit making engagement with the stationary contact I3 and thus open the high potential circuit. Now, should it happen that an overload condition occurs upon the high potential circuit, either upon a closing of the circuit interrupter contacts or at any time thereafter, the overload relay lili wiil respond to this condition and cause a direct current impulse to be transmitted through the inductively coupled control circuit between the direct current control eircuit conductors 4d, 6g and the electro-magnetic device d3. This will cause the device d3 to instantly operate and trip the toggle mechanism formed by the links 35 and 35 and thus permit the spring 27 to immediately withdraw the moving contact I9 from its cooperating stationary contact i3 and thus open the high potential circuit independently of the mechanical power supplying mechanism which operates through the series of insulators In this latter event, the various elements of the operating mechanism will. assume the positions illustrated in Figure 2 of the drawings. At the same time, since the electromagnetic means that controls the latch '5l oi the mechanical operating mechanism is shown as responsive to current from the low potential control circuit conductors and fi through the contact 3i of the ovenoad relay llil, the mechanical operating mechanism will also be set in operation substantially simultaneously with the operation oi the toggle tripping device 53 which controls -lthe toggle mechanism formeel by the links 35 and However, due to the small inertia mass of this latter toggle mechanism, as compared to the larger inertia mass of the mecanical operating mechanism, the opening of the circuit interrupter contacts will occur immeditely following a collapse of the toggle links 35 and 3G and before the mechanical operating mechanism has fully completed its operating movement. Therefore, the circuit in errupter will respond to an overload in a substantially shorter period than would be the case if reliance were had solely upon the mechanical power operating mechanism to open the circuit interrupter in response to such an overload. rihis operation is clearly illustrated by Figures 2 and 3 of the drawings, where in the former iigure the toggle formed by the links 35 and 53 is shown as having been collapsed by an operation of the toggle tripping device il?, prior to a collapse of the toggle formed by the link and 31%, which latter links are later collapsed, as shown in the latter figure, by the then initiated operation or" the mechanical operating mechanism. es shown in this latter figure of the drawings, it will be noted that the collapsing of the toggle icrmed by the links 38 and 3 ey the operation of the mechanical operating mechanism causes the lever arm 33 to move downwardly and thus reset the toggle formed by thelinks @5 and in an overcenter position against the abutment El where, upon a subsequent closing operation of the mechanical operating mechanism, the toggle formed by the links 33 and may be again extended to reclose the circuit interruptor, as will be readily understood. While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and iilustrated specific devices and arrangements, I desire to have it understood that this invention is not limited to the speci-lic means disclosed, but :lay be embodied in other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and it is desired to claim it so that all such changes as come within the scope of the appended claims are to be considered as part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. In a system of control for high voltage circuit interrupters, the combination of a high potential circuit, a circuit interrupting means for opening and closing said high potential circuit an operating means for said circuit interrupting means located and operating in a zone of high potential, a mechanical power supplying means for said operating means located at ground potential and connected to said operating means through an insulated mechanical connection, electro-magnetic means also located and operating in a zone of high potential for rendering said operating means inoperative to control said circuit interrupting means in the event of an overload on the high potential circuit, a rela-y responsive to load conditions upon said high potential circuit, a low voltage control circuit responsive to an operation of said relay for controlling the operation oi said mechanical power supplying means, and an inductive circuit forming an insulated electrical energy transmitting connection between said low voltage circuit and said electro-magnetic means for controlling the operation of said operating means in the Zone of high potential independently oi said mechanical power supplying means in the event of an overload on the high potential circuit.

2. In a system of control for high voltage circuit interrupters, the combination of a high potential circuit, a circuit interrupting means for opening and closing said high potential circuit, an operating means for said circuit interrupting means located and operating in a zone of high potential, a mechanical power supplying means for said operating means located at ground potential and connected to said operating means through an insulated mechanical connection, electro-magnetic means also located and operating in a Zone of high potential for rendering said operating means inoperative to control said circuit interrupting means in the event of an overload on the high potential circuit, a relay responsive to load conditions upon said high potential circuit, a low Voltage control circuit responsive to said relay for controlling the operation of said mechanical power supplying means, and an inductively coupled impulse transmitting circuit also responsive to said relay and forming a high potential insulated control connection between said low voltage circuit and said electro-magnetic means operating in the Zone of high potential.

3. In a system of control for high voltage circuit interrupters, the combination of a high potential circuit, a circuit interrupting means for opening and closing said high potential circuit, an operating means for said circuit interrupting means located and operating in a zone of high potential, a mechanical power supplying means for said operating means located at ground potential and connected to said Operating means through a high potential insulated mechanical connection, a current impulse responsive means also located and operating in the zone of high potential for controlling said operating means in the event of an overload on the high potential circuit, a low voltage source of direct current for controlling said mechanical power supplying means, an inductively coupled impulse transmitting circuit forming a high potential insulated controlling circuit between said source of low voltage current and said current impulse responsive means, and a relay responsive to overload conditions upon said high potential circuit adapted to connect said mechanical power supplying means to said souce of direct current and also cl se said inductively coupled impulse transmitting circuit, whereby said operating means will operate in the zone of high potential in response to said current impulse responsive means to open the circuit breaker independently of said power supplying means.

Ll. In a system of control for high voltage circuit interrupters, a high potential circuit, a. circuit interrupting means having terminal contacts through which said high potential circuit is connected, a contact bridging member cooperating with said contacts and adapted to open and close said high potential circuit, an operating mechanism located at ground potential for controlling the circuit opening and closing movements of said contact bridging member, an insulated mechanical power transmitting means extending from said operating mechanism to a point of high potential adjacent said contact bridging member, a tripfree mechanical connection between the eXtend ing end ci said insulated power transmitting means and said contact bridging member, a low voltage current supply circuit for controlling the operation of said operating mechanism, a low voltage current responsive device located in the Zone of high potential adjacent said high potential circuit io-r controlling said trip-free connection to permit a circuit opening operation of said contact bridging member independently of said operating mechanism, an inductive current impulse transmitting circuit forming an insulating electric energy transmitting connection between said current responsive device in the Zone of high potential and said low voltage circuit, and relay means responsive to load conditions upon the high potential circuit for controlling the operation of said low voltage current responsive device through said insulating inductive current impulse transmitting circuit in the event of an abnormal load condition upon said high potential circuit.

5. In a system of control for high voltage circuit interrupters, a high potential circuit, a circuit interrupting means having terminal contacts to which said high potential circuit is connected, a contact bridging member adapted to cooperate with said terminal contacts to open and close said high potential circuit, an operating mechanism located at ground potential for mechanically controlling the circuit opening and closing movements of said contact bridging member, an insulated mechanical power transmitting means eX- tending from said operating mechanism to a point of high potential adjacent said contact bridging member, spring means for biasing said contact bridging member to an open circuit position with respect to said terminal contacts, a trip-free mechanically operating connection between the end of said insulated power transmitting means and said contact bridging member for holding said contact bridging member in its closed circuit position against the action of said spring, a low Voltage current supply circuit for controlling the operation of said operating mechanism, a low voltage electromagnetic device located in the zone of high potential and remote from said operating mechanism for controlling the operation of said trip-free mechanically operating connection independently of said operating mechanism, an inductive current impulse transmitting circuit forming an insulating electric energy transmitting connection between said electro-magnetie device at high potential and said low voltage circuit, and relay means responsive to load conditions upon said high potential circuit for controlling said inductive impulse transmitting circuit, whereby said trip-free mechanically operating connection will be tripped and permit said spring means to move said contact bridging member into its open circuit position independently of said operating mechanism in the event of an abnormal load condition upon said high potential circuit.

6. In a system of control for high voltage circuit interrupters, a high potential circuit, a circuit interrupting means having terminal contacts, a contact bridging member adapted to co' operate with said terminal contacts lto open and close said high potential circuit, a mechanical power supplying mechanism located at ground potential for controlling the circuit openmg and closing movements of said contact bridging member, an insulated mechanical power transmitting means extending from said mechanical power supplying mechanism to a point of high potential adjacent said contact bridging member, a mechanical trip-free connection between the extending end of said insulated power transmitting means and said contact bridging member for releasing said contact vbridging member from said mechanical power supplying mechanism, an independent operating means for moving said ccntact bridging member to its open circuit position when released from said mechanical power supplying mechanism, a low voltage direct current circuit for controlling the operation of said mechanical power supplying mechanism, a current impulse responsive device located in the zone of high potential adjacent said high potential circuit and remote from said mechanical power supplying mechanism for controlling the operation of said trip-free connection independently of said mechanical power supplying mechanism, a relay responsive to current conditions on the high potential circuit, and an inductive current impulse transmitting circuit controlled by said relay and forming a high potential insulating circuit connection between said current impulse responsive device and said low voltage direct current circuit, whereby said impulse responsive device will operate said trip-free connection to release said contact bridging member and permit said independent operating means to open the high potential circuit as said relay is inuenced by load conditions upon the high potential circuit.

7. In a system of control for high voltage circuit interrupters, the combination of a circuit interrupting device having circuit controlling contacts to which the terminal ends of a high potential circuit may be directly connected, mechanical means insulated from and located at ground potential for controlling the operation of said circuit controlling contacts, relay means responsive to load conditions upon the high potential circuit for controlling said mechanical means, electro-magnetically controlled means located in the Zone of high potential for moving said circuit controlling contacts into lan open circuit position independently of said mechanical means, and an inductively insulated icontrol circuit for said electro-magnetically controlled means also controlled by said relay, whereby in the event of an overload condition upon the high potential circuit said electro-magnetically controlled means will operate independently of said mechanical means to open the high potential circuit through said circuit controlling contacts.

8. In a system of control for high voltage circuit interrupters, a high potential circuit, a circuit interrupter having a stationary and a relatively movable contact adapted to cooperate to open and close said high potential circuit, means for biasing said movable contact into an open circuit position with respect to said stationary contact, a mechanism located in a zone of high potential operating independently of said biasing means for imparting normal circuit opening and closing movements to said movable contact, an insulated mechanical power transmitting means extending from said operating mechanism and adapted to ybe driven by a source of mechanical power located at ground potential, a low voltage direct current source of power having electromagnetically responsive means for controlling the operations of said mechanical power transmitting means, relay responsive to load conditions upon said high potential circuit for contr-olling said low voltage direct current source of power, electro-magnetically controlled means also located in the zone of high potential for releasing said movable contact operating mechanism from said insulated mechanical power transmitting means, whereby said biasing means will become operative and move said movable contact into its open circuit position independently of said insulated mechanical power transmitting means, and an inductively coupled electrical impulse transmitting circuit forming a high potential insulating control connection between said low voltage direct current circuit and said electro-magnetically controlled means located in the zone of high potential.

9. In a system or control for high voltage circuit interrupters, a high potential circuit, a circuit interrupter having a stationary and a relatively movable contact adapted to cooperate in opening and closing said high potential circuit, spring means for biasing said movable contact into an open circuit position with respect to said stationary contact, an operating mechanism located in a zone of high potential for eiecting the normal opening and closing movements to said movable contact independently of said spring means, an insulated mechanical -power transmitting means for said operating mechanism adapted to be driven by a source of mechanical power located at ground potential, a direct current source of power having electro-magnetically responsive means for controlling the operations of said mechanical power transmitting means, a relay rendering said direct current source of power responsive to load conditions upon said high potential circuit, electro-magnetically controlled means located at the high potential end of said insulated mechanical power transmitting means for releasing said movable contact operating mechanism from said mechanical power transmitting means, whereby said spring means will become operative to move said movable contact into its open circuit position, and an inductive electrical ini-pulse transmitting circuit forming a high potential insulating means of control between said low voltage circuit and said electromagnetic means when said relay responds to load conditions upon the high potential circuit.

l0. In a system of control for high voltage circuit interrupters, a high potential circuit, a circuit interrupter for said high potential circuit having a movable circuit opening and closing element, an operating mechanism for said circuit opening and closing element insulated from ground and operating in a Zone of high potential, a power supplying means for said operating mechanism located at ground ypotential and arranged to mechanically control said mechanism through an insulated mechanical power transmitting connection, a low voltage direct current control circuit for controlling said power supplying means, electro-magnetic means operating in the high potential zone of the circuit interrupter for rendering said operating mechanism inoperative to retain said movable circuit opening and closing element in its closed circuit forming position, an inductively coupled high potential insulating circuit through which said electromagnetic means operating in the high potential zone of the circuit interrupter is controlled in response to the condition of said low voltage direct current circuit, and a relay for controlling said low voltage direct current circuit as determined by load conditions upon said high potential circuit.

11. In a system of control for high voltage circuit interrupters, a high potential circuit, a circuit interrupter for said high potential circuit having a movable circuit opening and closing element, an operating mechanism for said circuit opening and closing element insulated from ground and operating in a zone of high potential, an electro-magnetically controlled power supplying means for said operating mechanism located at ground potential and arranged to mechanically control said operating mechanism through an insulated mechanical power transmitting connection, a low voltage direct current circuit for controlling the operation of said electro-magnetically controlled power supplying means, an overload relay responsive to load conditions upon said high potential circuit adapted to control said low voltage direct current circuit in the event of an overload upon said high potential circuit, electromagnetic means also operating in the high potential zone of the circuit breaker for rendering said operating mechanism inoperative to retain said movable circuit opening and closing element in its closed circuit forming position, and an inductively coupled high potential insulating circuit for connecting said electro-magnetic means operating in the high potential zone of the circuit interrupter with said low voltage direct current circuit, whereby the operation of said electromagnetic means will be controlled by a direct current impulse from said low voltage direct current circuit when said overload relay operates in response to an overload upon the high potential circuit.

l2. In a system of control for high voltage circuit interrupters, the combination of a high potential circuit, a circuit interrupting means having normally open cooperating contacts adapted to be moved into engagement with each other to close said high potential circuit, an operating mechanism located at ground potential for imparting a circuit closing movement to said cooperating contacts, an insulated mechanical power transmitting means extending from said operating mechanism and adapted to move said cooperating contacts with respect to each other, a tripfree mechanism forming a mechanical connection between the extending end of said insulated power transmitting means and said cooperating contacts adapted when tripped to permit a circuit opening operation of said cooperating contacts independently of said operating mechanism, a low voltage current supply circuit for controlling said operating mechanism, a low voltage current impulse responsive device located in the zone of high `potential and in controlling relation with said trip-free mechanism, a normally open inductive current impulse transmitting circuit forming a high potential insulating electric energy transmitting connection between said current impulse responsive device and said low voltage circuit, and relay means responsive to load conditions upon the high potential circuit for completing said inductive current impulse transmitting circuit in the event of an abnormal load condition upon said high potential circuit, whereby said trip-free mechanism will operate and permit said cooperating contacts to move into open circuit relation with respect to each other independently of said operating mechanism.

ROY WILKINS.

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