US1566122A - Circuit-controlling device - Google Patents

Description

Dec. 15 1925 1,566,122

F. ROBERSON CIRCUIT CONTROLLING DEYICE Filed May 16, 1925 T'nvehtor': Fromk Roberson, e! His Attorney Ill) Patented Dec. 15,

UNITED STATES PATENT OFFICE.

FRANK ROBERSON, OF GARY, INDIANA, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW'YORKL CIRCUIT-CONTROLLING DEVICE.

Application filed May 16, 1925.

To all whom it may concern:

Be it known that I, FRANK RoBERsoN, a citizen of the United States, residing at Gary, in the county of Lake, State of Indiana, have invented certain new and useful Improvements in Circuit-Controlling Devices, of which the following is a specification.

This invention relates to circuit controlling devices and more particularly to circuit interrupters of the high speed type which are electro-magnetically held closed and arranged to quickly and positively open to in terrupt an electric circuit in response to predetermined conditions such as for instance an overload on the circuit.

The principal object of the present invention is to provide an improved form of high speed circuit interrupter of the above character whereby the speed at which the circuit is interrupted may be practically doubled.

A further object of the invention is to provide an improved form of circuit interrupter of the above type which is arranged to trip free should an excessive overload current flow upon the closure of the interrupter.

Although not necessarily limited thereto, the present invention is particularly well adapted to be applied to high speed electro magnetic circuit interr'upters of the type described and claimed in the reissued Patent No. 15,441 issued August 29, 1922 to John F. Tritle. In the Tritle type of circuit interrupter a movable switch arm is strongly biased to the circuit interrupting position and is arranged to be held in circuit closing engagement with the stationary switch contact cooperating therewith by the magnetic attraction of an electromagnet. Suitable means such as abucking bar energized responsively to the current through the interrupter is provided for controlling the holding (-ilectromagnet to permit the switch memher to open quickly in accordance with its bias upon the occurrence of overload conditions in the controlled circuit. Quick acting circuit interrupters constructed and arranged in the manner described. in the above applicatlon are eminently successful in protecting electrical apparat-us such as dynamo electric machines from heavy rushes of overload or short circuit current which otherwise might cause the machines to flash over in a very short interl of ti e, However, when this type of Serial No. 30,738.

circuit interrupter is constructed in accordance with my present invention, the speed at which the overload or short circuit current is interrupted is practically doubled. Thus by means of my present invention the Tritle type of interrupter is rendered-capable of still more effectively protecting against heavy rushes of current such as oocurunder severe short circuit conditions or the like.

In carrying the invention into efi'ect in a preferred form, I provide the circuit interrupter with a pair of cooperating independently movable switch members which are each strongly biased to the circuit interrupting position and are arranged to be operated into circuit closing engagement. Also I provide an electromagnet preferably having separate poles for magnetically holding each of the switch members in the circuit closing position. In order to simultaneously release the members to permit them jointly to interrupt the circuit at twice the interrupting speed of a single movable switch member, I associate a conductor or winding with the several poles of the holding electromagnet so as to simultaneously control the attractive force thereof to permit the switch members to move quickly to their respective circuit interrupting positions. The resultant separation of the cir cuit controlling switch members is effected at such a high rate of speed as to almost instantly interrupt even heavy short circuits.

Furthermore, since the cooperatingswitch members in the preferred form of my improved circuit interrupter are independently movable to and from the circuit closing posi tion the interrupter is capable of affording overload protection from the instant that the controlled circuit is closed. This is due to the fact that theone of the switch members which is initially operated to and held in the circuit closing position is free to be released instantly should an overload current How in the controlled circuit when the second switch member is operated to the circuit closing position.

For a. better understanding of my inven tion, reference is had to the following de scription taken in connection with the accompanying drawing in whichFig. 1 diagrammatically illustrates a high speed electromagnetic circuit interrupter embodying the invention for the purpose of explaining the principles thereof, and Fig. 2 is a detailed view showing the pole construction of the holding electromagnet with which the interrupter shown in Fig. 1 is provided.

The novel features and combinations which I believe to be characteristic of my invention are pointed out with particularity in the appended claims. 7

Referring to Fig. 1, the circuit interrupter embodying my invention comprises essentially the two cooperating independently movable switch members 10 and 11 which are pivotally mounted to rotate respectively about the pivots 14c and 15 and are each strongly biased to the circuit interrupting position by means of the biasing springs 12 and 13 respectively. It will be observed that the movable switch members are provided with suitable yielding circuit controlling contacts 16 and 17 respectively which are arranged to move into circuit closing engagement when the switch arms 10 and 11 are operated to their respective circuit closing positions.

In order to hold the switch members 10 and ll in the circuit closing positions in which they are shown, the magnetic members 18 and 19 are suitably attached repectively to the switch members 10 and 11 and are arranged in magnetic attractive relation with the poles of the holding electromagnet 20. As shown, the holding electromagnet 20 is provided with a holding winding 21 which. it will be understood normally is connected to be energized from a suitable source of supply not shown in the drawing. The mag-- netic structure of the holding electromagnet 20 is divided and ofiset so as to provide a separate pair of poles for holding each of the magnetic members 18 and 19, as more clearly shown in Fig. 2 Thus it will be seen that the operating flux of winding 21 which passes through the pair of poles serves'to magnetically attract the member 18 and thereby hold switch member 10 in the circuit closing position when it is operated thereto through the agency of suitable closin'g mechanism such as the combined manual. and electron'iagneti'c closing device 23 illustrated in the drawing. In a similar manner, the magnetic member 19 is held under the magnetic influence of the pair of poles 2a to maintain the movable switch member 11 in the circuit closing position when. operated thereto by' the closing device It will be observed that the conductor 26, as shown, is connected in the circuit controlled by the interrupter which extends from the terminal 27 through a flexible connector to the contact 17, thence through the contact 16 and a flexible coiinector connecting the latter to conductor 26 which is connect'ed to the other terminal 28 of the interrupter. An intermediate portion of conductor 26 :is 'o'fl'set and l'ooji'd, as more may shown in Fig. 2, to form a buckling bar for each of the pairs of poles 22 and 2t or the holding electromagnet 20 in order to effect the simultaneous release of the switch members 10 and 11 upon the occurrence of an overload current in the circuit controlled by the interrupter. It will be evident, however, that other suitable means energized responsively to the current of the interrupter may be employed for controlling the holding electromagnet 20 to effect the simultaneous release of the switch members 10 and 11 if desired.

With the circuit interrupter shown in Fig. 1 connected in a power circuit to afford overload protection, the operation is as follows r-VVhen the current in the power circuit controlled by the interrupter is of normal value switch members 10 and 11 are held in their respective positions, as shown, with the circuit controlling contacts 16 and 17 in circuit closing engagement. How-- ever, upon the current in the controlled circuit increasing to an abnormal value due to overload, short circuit, or other abnormal conditions, the current passing through conductor 26 is increased correspondingly. In a manner fully explained in the Tritle reissue patent previously mentioned, the increased flow of current through the offset looped portion of conductor 26 forming the bucking bars for the poles 22 and 24: of holding electromagnet 20 serves to shift or transfer the flux of holding winding 21 passing through the magnetic members 18 and 19 away from the magnetic members through the air gap between the inner portions of the respective pair of poles. In this way, the attractive efiect of holding electromagnet 20 upon each of the magnetic members 18 and 19 is reduced sufficiently to permit the biasing springs 12 and 13 to quickly operate the switch members 10 and 11 substantially simultaneously to their respective circuit. interrupting positions. The combined movements-of switch members 10 and 11 effects the separation of the circuit controlling contacts 16 and 17 at an extremely high rate 01 speed. This permits the interrupter to safely and successfully break the circuit almost instantly even though an extremely heavy overload. or short circuit current is flowing therein.

The reclosure of the interrupter prefer ably is effected by operating the switch members 10 and 11 successively to their respective circuit closing positions by means oi the closing devices 23 and respectively. Thus, when the circuit controlling member 10 is ii' itially operated to the closed pO'Sltlflil and held therein by the magnetic attraction between the poles 22 of holding electromagnet 20 "and the magnetic member 18, member 1O willbe free .to be in antly operated to the': circuit interrupting p'esi lon y the biasing spring 12 should an overload current flow through the conductor 26 when the switch member 11 is operated to carry the circuit controlling contact 17 into circuit closing engagement with the contact 16.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof but I would have it understood thatthe apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is l. A high speed circuit interrupter com prising a pair of cooperating independently movable circuit controlling contacts each biased to a position to interrupt the circuit jointly controlled thereby, an electromagnet having a magnetic movable member for controlling each of said contacts, the said electromagnet having a separate flux path for magnetically holding each of said members in the circuit closing position, and means responsive to the current in the circuit controlled by the interrupter for simultaneously controlling the flux in said paths to release the said members.

2. A. high speed circuit interrupter comn'ising a pair of cooperating independently movable switch members operable into circuit closing engagement and each biased to the circuit interrupting position, an electromagnet having a separate pair of poles for magnetically holding each of said members in the engaging position, and means energized responsively to the current in the circuit controlled by the interrupter and arranged to control the flux through said poles to release said members substantially sinmltaneously.

3. A high speed circuit interrupter comprising a pair of pivotally mounted cooperating switch members each biased to the circuit interrupting position and each having a movable magnetic member attached thereto, a normally energized electromagnet having poles for separately holding each of said magnetic members when the corresponding switch member is operated to the circuit closing position, and means responsire to the current in the circuit controlled by the interrupter for controlling the magnetic attraction between said poles and said members to release the members substantially simultaneously under predetermined current conditions.

t A. high speed circuit interrupter con1- 1 ing a pair of pivotally mounted cooperfiring switch members operable into circuit closing engagement and each biased to the circuit interrupting position, a pair of movable magnetic members, each mechanically connected to a corresponding one of the said switch members, a normally energized electromagnet having separate poles for magnetically holding each of said magnetic members when the corresponding switch member is operated to the circuit closing position to hold the same therein, and a conductor connected to be energized responsively to the current in the circuit controlled by the interrupter and associated with said poles to control the flux thereof to release said magnetic members to permit said switch members to move out of engagement when the current in the controlled circuit exceeds a predetermined value.

5. A trip free circuit interrupter comprising a pair of cooperating independently movable circuit controlling members each biased to the circuit interrupting position, means for separately operating each of said members to the circuit closing position,

means for separately holding each of said members in the circuit closing position com prising an electromagnet, and means responsive to the current in the circuit controlled by the interrupter for controlling the said electromagnet to release one of said members when the current exceeds a predetermined value upon the operation of the other member to the circuit closing position.

6. A trip free circuit interrupter comprising a pair of cooperating independently movable switch members operable into circuit'closing engagement and each biased to the circuit interrupting position, an electromagnet for separately holding each of said members in the engaging position, and means responsive to the current in the circuit controlled by the interrupter for controlling the said electromagnet to release one of-said members when the current exceeds a predetermined value upon the op eration of the other member to the circuit closing position.

7. A high speed trip tlt'ree circuit interrupter comprising a pair of pivotally mounted cooperating switch members each biased to the circuit interrupting position and each having a movable magnetic mem ber attached thereto, a normally energized GlGCtl'Oll'lfigIlOt having separate poles for holding each. of said magnetic members when the corresponding switch member is operated to the circuit closing position, and a conductor connected to be energized responsively to the current in. the circuit controlled by the interrupter for controlling the flux through said poles to release one of said members when the current exceeds a predetermined value upon the operation of the other member to the circuit closing position.

In witness whereof I have hereunto set my hand this 7th day of Ma y, 1925.

FRANK ROBERSON.

Images