US1734982A - Electric-circuit interrupter - Google Patents

Description

Nov. 12, 1929. M. M. SAMUELS ET AL 1,734,982

I ELECTRIC CIRCUIT I N'I'ERRUPTER Filed March 29, 1922' 4 Shoots-Sheet 1 W I 'Qurzce anzue wlueas \75667 cfznzon.

Nov. 12, 1929. M. M. SAMUELS ET AL 3 ELECTRIC CIRCUIT INTERRUPTER Filgd March 29 1922 4 Sheets-Sheet 3 Nov. 12, 1929- M. M. SAMUELS ET AL.

ELECTRIC CIRCUIT INTERRUPTER 4 Sheets-Sheet 4 Filed March 29 1922 fat/67226119.- J [aurzce JZ 5airzuels.

witness Patented.Nov.12,192 I r 1,734,9s 2

UNITED STATES PATENT. FFICE momenm. smears AND JOSE! axon, or NEwYonx; n, Y. ELEc'rmc-cmcm'r m'mnnuma V Y I Application filed larch 29, 1922. Serial No. 547,748

Our invention relates to electric circuit inanism during the starting f period of the 'terrupters, and has particular reference to motor. 'interrupters used for the protection of electric A further object of our inventionconsists circuits against overload and short circuit in the provision of means for preventing the a conditions. closing of the circuit provided current'in 55 It is one of the objects of our invention to excess of a predetermined amount is flowing provide an interrupter which is particularly, through such circuit. V although not exclusively, adapted for use A further object of our invention consists with lighting or small power circuits where in providing manually operated means by formerly switches and fuses were employed. which at any time the circuit may be opened so The construction of circuit interrupters or and further in the provision of means clearly breakers has heretofore been such that it was indicating to the observer or operator necessary to make them of too large size to be whether the circuit controlled by the intermounted in standard sized cabinets, the size rupter is open or closed.-

of these cabinets, and particularly the depth These and other objects of our invention 65 thereof, being limited to conform tothe diwill be more readily understood by reference mensions of partition walls of standard thickto the accompanying drawings, which show ness. a preferred embodiment of our invention;

The construction of our improved circuit and in which i Q interrupters, on the other hand, is such that Figure 1 is a plan of the interrupter with 70 they may readily be made of small size and the protecting cover removed therefrom; easily accommodated in the standard sized Figure 2 is a longitudinal section through cabinets, and are therefore adapted for use in the interrupter, the cover being shown in connection with lighting and small power cirplace, and two of the contacts and the mecha- 5 cuits in which cabinets are usually provided nism immediately associated therewith being 7 for the circuit protecting devices. shown in elevation;

It is a further object of our invention to Figure 3 is a transverse section taken on provide a circuit interrupter having an overline 3-3 of Figure 1; load device which can be accurately, set and Figure 4 is a transverse se tion taken on then sealed or locked, thus insuring that the line L-4 of Figure 1; o interrupter will always open the circuit when Flgure 5 1s a transverse section taken on a current in excess of a predetermined amount line 5-5 of Figure 1; passes through such circuit. This resultcan- Figure6 is a transverse section taken on not be accomplished by means of fuses, since 1ne. 0f Flgllle 1; v the spacing of the fuse holders or clips is such g IS an devil-151011 811d P 11 1 that fuses of various ampere capacities may sectlpqal Vlew h y the m 'P g 1 be inserted retaining and tripping mechamsm 111 open A further advantage of the provision in our P 9 I r 0 improved circuit interrupter ior sealing the Flgllre 8 1s gl slmllflrto Flgm'e 7, 9 overload device is to permit the use of our Z E g Posmon of the Parts when circuit interrupter for limiting the consumpmm as een rotated to an mtermedlate 'tiontion of electric current thus re lacin de- POSI- V mand meters and similar devices. D F1g1re9lsavlewsmlhrmmgure'ishmr 5 It is a still further object of our invention g g gg gg xg fig to Provide means by whlch the interrupter the position in which it is held before the opy be used P p of Startmg crating button has returned to its normal poprotecting fractional horsepower motors by i the use of suitable means for retarding the Fi i 10 i a i i il t Fi m 9, action of the automatic circuit opening mechx t th t th t ti ch i it is provided with a base 1 terial, on which turned to its normal position coincident with the return of the closing button to its normal position; 4

Figure 11 is a view similar to F igure 10, but showing the parts in an intermediate position after the tripping lever has engaged the catch or retaining lever;

Figure 12 is a view similar to Figure 9, but illustrating the position of the parts when the closing button is pressed down during overload Figure 13 is an enlarged sectional view of the spring-controlled means for holding\together the various parts of one of the sta tionary contacts, this section being taken on line 1313 of Figure 15;

Figure 14 is a rear elevation of one of the stationary contacts;

Figure 15 is a side elevation of one of the stationary contacts, such as shown in Figure 14;

Figure 16 is a front elevation of one of the'stationary contacts shown in Figure 14;

Figure 17 is a front elevation of the contact finger forming part of the stationary contact shown in Figures 14, 15 and 16;

Figure 18 is a fragmentary plan and partial horizontal section showing a modification adapted for use when the interrupter is used as a starter for motors;

Figure 19 is a. transverse section through the interrupter showing the parts illustrated in Figure 18;

Figure 20 is a fragmentary side elevation of (pertainof the parts shown in Figure 19; an

Figure 21 is a diagram showing the electrical connections for the circuit interrupter for a two-wire D. G. circuit or single-phase A. C. circuit.

The circuit interrupter of our invention of insulating ma base are mounted stationary contacts 2, 3, 4 and 5, four of these contacts being shown in the embodiment of our invention herein illustrated, but it is understood that the number of these contacts may be either increased or decreased without departing from the spirit of our invention.

Near the ends of the base 1 are located binding posts 6, 7, 8 and 9, through which the electrical connections of the circuit are made. Figures 1, 2 and 21 of the drawings illustrate the binding posts and connections adapted for a two-wire lighting circuit.

To the base 1: are secured the supports or brackets 10 and 11, in which is mounted a stationary shaft 12, it'beingapparent that this shaft is parallel to the line on which the stationary contacts 2, 3, 4 and 5 are placed, each of these contacts being mounted in a plane at right angles to the axis the shaft 12. A drum 13 of insulating material is loosely mounted on the shaft 12 and is free to rotate in opposite directions presently ments can be brought -into yielding engagement with the stationary contacts by rotation of the drum 13 in the direction of the arrow, as indicated in Figures 4 and 6. Circular barriers 18 of insulating material are provided on the drum 13 to separate the contacts from each other and prevent arcing over.

Rotation of the drum 13 and its contact segments 14, 15, 16 and 17 towards the corresponding stationary contacts 2, 3, 4 and 5 respectively is accomplished by means of a contact actuatin device, which in the preferred construction illustrated in the drawings consists of a push-button 19 having connected therewith a rack 20 engaging a pinion 21, which is rigidly secured to a' spring casing 22 loosely mounted uponthe stationary shaft 12. F.

A second spring casing 23 is rigidly connected to the end of the drum 13 and is adapted to rotate around the shaft 12. A spring-controlled pawl 24 mounted on the spring casing 22 normally engages the projection 25 on the spring casing 23 when the various parts are in the position in which the circuit controlled by the interrupter is open. I

By referring to Figures 5, 7, 8 and 9; the operation of the arts to which reference has Just been ma e will be clearly understoo By manually pushing down the pushbutton 19 and its attached rack 20, the latter will rotate the pinion 21 and the spring casing 22 to which it tion of the arrows, as indicated in Figures 5, 7 and 8. Due to this rotation, the pawl 24 mounted on the spring casing 22 and in engagement with the projection 25 will rotate the spring casing 23 with the spring casing 22,'thus placing under increased tension the helical spring 26 within the spring casing 23. When the parts are thus rotated into the position shown in Fi -ure 9, the contact segments 14, 15,16 and 1 have been brought into engagement with the stationary contacts 2, 3, 4 and 5 respectively and the circuit which the interrupter controls is therebyclosed. When the parts are brought into the position shown in Figure 9, the spring-controlled locking lever 27 'isis attached-in the direcpressure on the push-button 19, the latter 15 returned to its normal position shown in Figures. 2 and 5 on account of the return movement of the spring casin 22, which rotates back to its normal position from the position shown in Figure 9 to the position shownin Figure 10, the'projection 22 of the spring casing 22 being brought into engagement with the stop 28, so that further rotation of the spring casing 22 by its contained spring will'be prevented.

' The position of the parts as just described represents the closed position of the circuit interrupter,-as indicated in Figures 4 and 6. and the electrical circuit is completed as diagrammatically indicated inFigure 21. The circuit from binding post 6 to binding post 8 is closed through the stationary contact 2. the contact segment 14, the connection 29 between segments. 14 and 15, the stationary contact 3, and a conductor leading therefrom to the binding post 8. On' the other hand. the connection between binding posts 7 and 9 is made through stationary contact 4, contact segment 16, conductor 29, connecting contact segments 16 and 17, stationary contact 5, and a conductor leading from stationary contact 5 to binding post 9, the coil 30, for the pur osehereinafter described, being inserted in t e circuit between the stationary contactor5 and the binding post 9.

The connections above described from the binding post to the stationary contacts, as well as the binding posts themselves, are preferably molded into the base 1 to secure good insulation and to cheapen the manufacture. Other parts, such as the. stationary contact supports and the connections for the movable contact segments, may also be molded into the base or the contact drum, as the case may be, for the same reasons.

Coil 30, above mentioned, forms part of an electromagnet and is wound around a laminated core 31 which is secured to a frame 32 mounted on the base 1. Pivotally connected to the frame 32 is alaminated armature 33, to which is fastened the tri ping lever 34.

' Byreferring to Figure'2 o the drawings,

' 36, which serves to depress the armature and it will be seen that the laminations ofthe electromagnet core 31 and of the armature 33 are identical in shape, for the purpose of simplifying the manufacture. The armature 33 also has secured to-it a finger 35 which serves as an indicator for the calibration of.

the electromagnet for-various current capacities. The calibration scale is preferably located on the frame 32, .but'is not indicated in the drawings. The armature 33, with the tripping lever 34 attached, can also be moved by means of a spring-controlled push-button bring the tripping lever 34 into engagement 2 with the locking, lever 27, thereby removing the engagement of the latter with theprojection 25 on thespring casing 23.

The calibration of the electromagnet is effected by varying the air-gap between the stationary core 31 and the armature 33 by means of the calibrating screw 37 shown in Figure 3. In order to prevent tampering with the set-screw37 a cover 38 is rovidedover said screw, and this cover can e sealed by means of a wire 39 passing through small registering openings in the cover 38 and frame 32.

In case of an overload or short circuit,

the core 31 will be energized to a sufficient extent by the excess current passing through the coil 30, so that the armature 33 will be attracted and rotation of the armature on its pivot 40 against the tension of the spring 42 will be efiected. At the same time, the tripping lever 34 secured to the armature 33 will be brought into engagement with the catch lever 27, forcing the right hand end of this lever downward, as indicated in Figure 11, and raising the left hand end of the same, this catch lever being thus moved upon its pivot 41. The lever 27 will thus be disengaged from the projection 25 on the spring casing 23, and the latter will be enabled to rotate in the direction indicated by the arrow in Figure 11 back to the position shown in Figure 7, by reason of the action of the spring 26.

The drum 13 is of course rotated with the spring casing 23, thereby removing the contact segments 14, 15, 16 and'17 from engagement with the stationary contacts 2, 3, 4 and 5 respectively, and quickly opening the circuit. The rotation of the spring casing 23 and the drum 13 is limited by the stop 28, on theqframe 32, the projection 25. on the spring casing 23 being brought into engagement with the stop 28.

As soon as the electrical circuit is opened in the manner just described, the electromagnet made up of the core 31 and the core 30 is de-energized and the armature with its tripping, lever 34 is returned to normal position by the action of the spring 42.

The circuit interrupter may now be again closed in the manner previously described by depressing the push-button 19. If, however, during the closmg of the circuit interrupter excessive electric currents constituting an overload or short circuit should still prevail, it will be impossible to keep the circuit breaker closed, since the moment that excessive current flows through the coil 30, the armature 33 with the tripping lever 34 will again be depressed and will hold the catch lever 27 in the position indicated in Figure 12. -Under these conditions, when the ratchet 2O approaches its lowermost position, the pawl 24 will be automatically disengaged from the sprin casing 23 by engagement of the inner end 0 the catch lever 27 with the under side of a projection on the pawl 24, thereby lifting the latter out of engagement with the projection 25 on the spring casing 23, thus of the calibrating screw 37, not only will the circuit interrupter be opened upon the flowing of such excess current, but during the continuance of the excess flow, the circuit interrupter will instantaneously be opened again even though the push-button should manually be held in the depressed position.

The circuit interrupter constituting the subject-matter of our invention may also be used as a starting device for small power motors. It is well known that during the starting period of a motor, the starting current exceeds by a large margin the normal amount of current required for running the motor after the latter has once been started. Since, however, the motor must be protected against excessive currents during the running period, it is necessary to eliminate during the starting period any automatic means for opening the circuit interrupter.

According to our invention, the elimination of the automatic circuit opening fea tures of our device is accomplished by retarding the action of such automatic circuit opening means during the starting period of the motor. To accomplish this result, a dashpot 43 is provided, as indicated in Figures 18 and 19. A pivotally mounted operating arm 44 is adapted to engage the extension 45 of the locking lever 45, which is normally held in the position shown by the full lines in Figure 19 by means of the spring 45. The operating arm 44 is suitably connected with the piston 46 of the dash-pot 43. The operating arm 44 also has connected therewith the spring 47, so that the piston 46 of the dash-pot would normally be moved upwardly within the dash-pot and the upper end of the piston 46 would be approximately in the position indicated by the dotted line 48. In this position of the piston of the dash-pot, the operating lever 44 by engagement with the projection 45* of the locking lever 45 would move the latter so that the upper end of the same would be in the position indicated by the dotted line 49.

When the locking lever is in the position indicated in full lines in Figure 19, it will be evident that the'notch at its upper end will prevent the tripping lever 34 from being depressed, and will thus prevent the circuit interrupter from being automatically opened.

When it is desired to start the motor, the

push-button 19, with the attached ratchet frame 20, are depressed as previously ex- 44 and the piston 46 of the dash-pot to be moved into the positions indicated in full lines in Figure 19, at the same time the looking lever 45 being moved into the position shown in full lines by the action of the spring shown by the dotted line 48. The upper end of the locking lever 45 is moved in the manner. previously described to the position shown by the dotted line 49,, so that after the starting operation is completed, the full automatic features of the circuit interrupter may again become effective. If desired, the-upper end of the lever 45 may be provided with a plurality of notches 50, so that the locking lever may be broken ofli at any one of a plurality of points in accordance with the requirements for various starting currents. It will be evident that other methods might be used for eliminating the automatic features of the circuit interrupter during the starting period of the motor, as, for example, by short-circuiting the electromagnet coil 30 by bridging the contacts provided at the ends of the coil 30 through the operation of the push-button 19, a method which will be readily understood without illustration in the drawings.

In a circuit breaker, the contact tips may contact which is adapted for use in connection with our invention. It will be understood, however, that in this application we are not claiming the construction of the contact illustrated, as the same forms the sublocking ject-matter of a separate application. We

are, however, explaining the construction of the contact in order that the operation of our invention as a whole may be readily understood.

Each of the stationary contacts 2, 3, 4 and 5 consists of a rigid support 51 fastened to the insulating base 1. At its upper end, the sup port- 51 is provided with a projection 52, and towards its lower end has an opening 53, the projection 52 and the opening 53 serving to hold the contact finger 54, having a corresponding hole and projection, loosely in position, as indicated in Figure 15. In order to plained, this action causing the operating arm retain the contact finger 54 in its position, a

retainer 55 is provided with two cup-shaped members 56, one rigidly and the other loosely t1 and is thereby held in position.' It W11].

rupter is in closed be evident that the removal of the contact finger 54 is readily accomplished by turning the retainer 55 to an angle of ninety degrees and removing the retainer by slipping the projection 58 through the vertical slots 59 and 61, after which a new contact finger can be placed in position if desired. The elec trical connection of the contact finger 54 with a main conductor is accomplished by the flexibleconductor 62, which is held in engagement with the finger 54=by thespring 57 this spring also serving to enable the contact finger to have a yielding connection with the "corresponding contact segment contained on the rotatable drum.

In order to protect the device against damage, a removable metal cover 63 is provided, which can be held in place and sealed by means of the projections 64 on the frame members 10 and 32, which project through suitable openings in the casing. The cover 63 also has openings for the closing button L9 and the tripping button 36 and for an indicating device. The latter consists of two separate and distinctively'marked disks 65 and 66 secured to the rotatable contact drum. 13 in such manner that one disk is opposite an opening 67 in the cover 63 when the circuit interosition, and the other disk is brought opposlte the opening when the circuit interrupter is in the open position.

Fastened to the contact drum 13 are angular extensions 68, which are brought into engagement with the catches 69 on the cover 63 when the circuit breaker is in closed position, thus preventing the removal of the cover 63 when the circuit interrupter is closed,but allowing its removal when the same is open. It will be apparent to those skilled in the art that many changes could be made in the detailed construction of the specific embodiment of the invention we have described without departing from the spirit and scope of our invention. I

Whatweclaimis:

1. In a circuit interrupter, the combination with a rotatable insulating drum, of a contact carried by said drum, a stationary contact adapted to be engaged by the contact of said drum upon rotation of the latter, a spring tending to normally rotate said drum in a direction to remove the contact of said drum from engagement with said stationary contact, a housing for said spring mounted on said drum, a projection on said, housing, and means for rotating said drum in the opposite direction in or er to bring the contact on said drum into engagement with said' stationary contact, -'said last-mentioned means consisting of a spring-controlled member rotatable independently of said drum, a

pinion carried by said member, a manually operated rack engaging-said pinion, and a pawl carried by said spring-controlled member and adapted to en age the projection of said spring housing, w ereby upon actuation of said rack said spring-controlledmember will be rotated and the pawl thereon will cause rotation of said drum and upon release of pressure upon said rack said spring-controlled member will be rotated back to its normal position therebycorrespondingly returning said rack to its normal position.

2. In a circuit interrupter, the combination of a. movable insulating member, a contact carried by' said insulatin member, a stationary contact adapted'to engaged bythe contact on said insulating member, means tending to normally move said insulating member to removethe contact thereon from engagement with said stationary contact,

locking means forholding said insulating member in the position in which the contact thereon engages said stationary contact,

1means for automatically releasing said lock ing means upon passage of current in excess of a predetermined maximum, means for blocking vthe operation of said releasin means, said blocking means beingactuate by the means for moving said insulating member into the position in which the contact thereon enga es said stationary contact, a dash-pot, an spring-operated means controlled by said dash-pot for moving said blocking means into inoperative position.

3. In a circuit interrupter, in combination, a rotatable drum,fa contact carried by said drum, a stationary contact adapted to be engaged by the contact on said drum upon rotation of said drum, spring means biasing said drum to a position to disengage said contacts, a spring-controlled member rotatable independently of said drum, means for operating said spring-controlled member, a pawl carried by said spring-controlled member adapted to communicate turning movement to said drum to bring said contacts into engagement and to return to its biased position when pressure is released from said sprin controlled member, a detent for holding sa1d drum in contact making position, said detent includin a lever, movable means responsive to the ow of current through said circuit interrupter adapted to engage said lever for releasing same, and delayed action means comprising an abutment for said movable means to prevent the release of said detent and adapted to move out of abutting relationship with said movable means after a predetermined interval of time.

4. In a circuit interrupter, a combination of a'movable insulating member, a contact carried by said insulating member, a sta-- 'tionary contact adapted to be engaged by the contact on said insulating member, means tending normally to move said insulating member to remove the contact thereon from engagement with said stationary contact, latch means for holding said insulating member in the position in which the contact thereon engages said stationary contact, means for automaticall releasing said latch means upon passage 0 current in excess of a predetermined maximum, a detent for preventing action of said releasin means, said detent including a lever, mova le meansresponsive to the fiow of current through said circuit interrupter adapted to engage said lever for releasing same, and delayed action means comprising an abutment for said movable means to prevent the release of said detent and adapted to move out of abutting relationship with said movable means after a predetermined interval of time.

5. In a circuit interrupter, a combination of a movable insulating member, a contact carried by said insulating member, a stationary contact adapted to be engaged by the contact on said insulating member, means tending normally to move said insulating member to remove the contact thereon from engagement with said stationary contact, latch means for holding said insulating member in the position in which the contact thereon engages said stationary contact, means for automatically releasing said latch means upon pas: sage of current in excess of a predetermined maximum, a detent for preventing action of said releasing means, and conjoint means for controlling said detent, said conjoint means including electromagnetic means for releasing said detent with delayed action means for delaying the action of said electromagnetic means, said conjoint means also including a manually operable member for releasing said detent independently of said electromagnetic means.

6. In a circuit interrupter, in combination, a rotatable drum, a contact carried by said drum, a stationary contact adapted to be enga ed b the contact on said drum upon rotatlon 0 said drum, spring means biasing said drum to a position to disengage said contacts, a spring-controlled member rotatable independently of said drum, means for operating said spring-controlled member, a pawl carrled by said spring-controlled member adapted to communicate turning movement to said drum to bring said contacts into en- 1 gagement and to return to its biased position when pressure is released from said springcontrolled member, a detent for holding said drum in contact making position, and conjoint means for controlling said detent, said conjoint means including electromagnetic means for releasing said detent with delayed action means for delaying the action of said electromagnetic means, said conjoint means also including a manually operable member for releasing said detent independently of said electromagnetic means.

7. In a circuit interrupter, in combination, a rotatable drum, a contact carried by said drum, a stationary contact adapted to be engaged by the contact on said drum upon rotationof said drum, spring means biasing said drum to a position to disen age said contacts, a spring-controlled mem r rotatable independently of said drum, means for operating said spring-controlled member, a pawl carried by said spring-controlled member adapted to communicate turning movement to said drum to bring said contacts into engagement and to return to its biased position when pressure is released from said spring-controlled member, a detent for holding said drum in contact making position, and conjoint means for controlling said detent, said conjoint means including electromagnetic means for releasing said detent with delayed action means for delaying the action of said electromagnetic means, said conjoint means also including a manually operable member for releasingsaid detent independently of said electromagnetic means.

8. In acircuit interrupter, a combination of a movable insulating member, a contact carried by said insulating member, a stationary contact adapted to be engaged by the contact on said insulating member, means tending normally tomove said insulating member to remove the contact thereon from engagement with said stationary contact, latch means for holding said insulating member in the position in which the contact thereon engages said stationary contact, means for automatically releasing said latch means upon passage of current in excess of a predetermine'd maximum, a detent for preventing action of said releasing means, and conjoint means for controlling said detent, said conjoint means including electromagnetic means for releasing said detent with delayed action means for delaying the action of said electromagnetic means, said conjoint means also including a manually operable member for releasing said detent independently of said electromagnetic means.

Signed at New York in the county of New York and State of New York this 28th day of March A. I). 1922.

MAURICE SAMUELS.

J OSEF AMON.

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