US957335A - Automatic circuit-breaker. - Google Patents

Description

C. T. HENTSGHEL.

AUTOMATIC CIRCUIT BB'EAKER.

APPLIOATION FILED SEPT. 10, 1908.

Patented May 1o, 1910.

3 SHEETS-SHEET 1.

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CHARLES. T HENTEJCHLL.

. ATTY.

WITNLEIEICS C. T. HENTSCHEL.

UTOMTIC GIRGUT BREAKER.

APPLICATION MLBD SEPT.10,190B.

957,335; Patented May 1e, 1910.

3 BHEETB-SHBET 2.

2 1 h ll WITNEx-IEE:

i W CHARLES T. HENTECHEL..

W7 ATTY,

C. T. HENTSGHEL.

AUTOMATIC CIRCUIT BREAKER.

APPLICATION FILED SEPT. 10, 1908.

Patented May 10, 1910.

3 SHEETB-SEEET 3.

, mvN-VDRZ EHAHLEI T. HENTEEHEL UNITED STATES PATENT OFFICE.

I CHARLES T. HENTSCHEL, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

' ping member which disconnects the operatand permit it to act when the current in AUTOMATIC cinemas-Bananen.

Sp'ecication of Letters laten't.c Patented May 10, 1910.

Application led September 1Q, '1 908, Serial No; 2,396.

f'ollowingis a specification.

My'invention relates-to automatic circuit bi-ea (ers, and more particularly to circuit breakers which are rendered `non-closable 'on overload by a disengageable connection between the operating handle and the contacts 0f the circuit breaker, with a trip coil 'arranged to actuate the disengageable connection and 'thereby disconnect the operating handle from Ithe contactsl when an attempt is made to close the circuit breaker while an overload is on the circuit.

The great pressure which the operating handle must exert'on the contacts in order to close a large lcircuit'breaker tends to lock the disengageable connection and a large and expensive trip coil must be used to fuinish the power required to disconnect the operating handle from the contacts. Since a large trip coilis expensive and consumes considerable current, the object of my invention is to improve and simplify nonclosable circuit breakers by providing a tripping mechanism which is operated by a small and cheap trip coil, and which will have sufficient power tol positively disconnect the handle fromthe contacts under allconditions.

In carrying out my invention the triping handle from the contacts is actuated by stored energy, and the only function of the trip coil is to release the-tripping membr t e circuit exceeds aI redeterminedlimit. The vork required to isconnect the handle from the contacts is performed -by the energy stored in the 4tripping mechanism, and since the'amount of this energy may be made as greatas desired the operating handle is positively disconnected from the contacts, even` Whe-regreat pressure is exerted on' the confor operating' the tri ping mechanism is.

tacts by the operating handle. The energy preferably derived rom the` operating mechanismvl ofthe switch by any suitable connection and is stored in any suitable op-:

erating device, such' as a spring put under -s't'rain by the operating mechanism of the switch and normally prevented from operat- -iiig the tripping mechanism bymeans of a -la-tch or detent controlled by the `trip coil. In the preferred constructionthe disen- .gageable or. collapsible connection between the operating handle and the contacts ofv the circuit breaker is a toggle, which is normallyE slightly, overset to form a rigid and positive connection between the operating .handle and the contacts, but which in effect disconnects the yhandle from the contacts `when collapsed oi .broken by the tripping device. The parts are preferably `so arranged lthat the tripping mechanism strikes :the toggle a hammer blow andthereby causes -itto collapse even though the operating han- -dle is exerting great pressure on the contacts through the toggle. After the circuit 4breaker is opened, dueto the breaking of ythe lcollapsible toggle, the operating handle must;be moved to straighten outthe toggle beforeftlie circuit breaker can be closed, and in the preferred arrangement this prelimmary-movement of lthe operating handle incident toetheclosing yof the switch is ntilized torestore the, tripping mechanism to its normal condition .and to store up in a spring or similar operatingdevice enough Aenergy -to enable the tripping.mechanism to break the collapsible toggle.. By the time the toggle vis straightened and forms a rigid connection between .the operating handle and the contacts the tripping mechanism is set andready to operate, and as the operating handle is moved to close the .circuit breaker the trip coil will release the tripping mechanism as soon as the contacts engage if an overload is present on the circuit, thereby causing the collapsible toggle to break and open-the circuit breaker.-

My invention will be best understood in connection with the accompanying drawings, which illustrate one of. the ,various forms in which it may be embodied and in which- A i f i Figure 1 is an `elevation of an oil switch or circuit breaker embodying my invention; Fig. 2 an enlar ed view in elevation of the collapsible togg e and tripping mechanism; Fig. 3 a plan view of t-he .device shown in Fig. 2; Fig. t a side view inzelevation, showing the collapsible ,toggle and the. tripping mechanism with the circuitLbreaker open andFig. 5 is-,a sideview in elevation, .showing the relation of 'the parts after the coilapsib'le toggle has been straightened and before the operating handie is moved close the circuit breaker.

rlhe kspecific form of automatic circuit breaker -shown in the drawings is a hand operated oil switch for handling heavy currents in a three-phase circuit, and comprises three masonry cells side by sine, each cell containing two oil pots arf* movable bridging Contact 3 i-'or contr one phase of the circuit. The movable c tact in each cell is carried on wooden rod extending through the of the cell connected to a parallel motion mechanism a, the three wooden rods being operai taneously by operatin coym arises horizontal o to the three The circuit break dendency to open bJ cted at one el d to arallel-motion mecha1 r end to the actuating connected' thi` io m disengageable or e 'tion 'to a suitable operatie 'sts 'the thrust oi the spring Y ed :torni of collapsible sh wn in the drawing, is a col- Y. f normally slightly overset and having 8 connected to the actuating rods and lint. f' a be l-e f) connected to one arm r actuating lever 10, which is pivotaiiy mounted on the framework of the circuit breaker and has the other arm connected by a rod 11 to an operating handle 12 mounted adiacent the end ci'l the switch in a convenient position. When the switch is closed, as shown in Fig. 1, the strain of the springs Z tending to open the switch is transmitted through the collapsible toggle to the locked operating handle 12 while the breaking of the collapsible toggle permits the springs 7 to move the actuating rod 6 to the lett, thereby raising all of the movable contacts simultaneously and opening the circuit breaker.

The preferred form of tripping mechanism for breaking the collapsible toggle when the current in the circuit exceeds a predetermined amount is best shown in Figs. 2 to 5, inclusive, and comprises a movable trip member 13 actuated by stored energy to strikethe overset collapsible toggle a hammer blow, thereby throwin it over center and permitting the circuit reaker to open. 1n the specific form shown in the drawings the trip member 13 is made in the form of a bell-crank lever havingthree arms 1li, 15, and 16, and in such a position that the arm 14 pivotally mounted in a frame 17 is thrown against the collapsible toggle with a hammer blow by means of any suitable energy-storing device, such as a spring 18,

2, and Vfhen the trip mechanism. is ir. normal condition, as shown in Figs. and

5, overset latching toggle holds t trip member immovable against the strain erted by the power-storing sprin@v 18, while the breaking of the latching` toggle releases the trip member 13, whereupon the sgr 18 contracts and causes the arm 1i cf trip member to strike the collapsible tot a heavy hammer l rl etching .niber against the eferably controlloJ ieunted in the 'n a position t toggle. rihe boli. rable way brefl rably by sonn cli a i i. CLL

circuits the which forms the core of the coil and by upon the occurrence oi a- 1 load. ,llhere the switch is used to contro-l a l" potential circuit a bell crank 22 is pivotcd to the frame 17, as shown in Fig. with one arm in a position to engage and lift 'the bolt 20 and the other arm connected, as shown in Fig. 1, through any suitable systcm of rods and levers 28 to trip coils carried on high potential insulators Q5 and connected directly in series with the leads of the circuit. ln either case only a small trip coil is required, since the only work the trip coil has to do is to lift the bolt 2O and break the latching toggle 19, whereupon the work of breaking the collapsible toggle to permit the circuit breaker to open is performed by the spring 18. The switch may also be tripped by hand when desired by means of a hand trip lever 26 with one end beneath the bolt 2O and the other end connected to a chain 27 which extends to point where it may easily be reached by the operator.

rlfhe energy for operating the trip member 13 may be stored in the spring 18 in any suitable way, but is preferably derived from the operating mechanism by means of some suitable connection betweenv the operating mechanism vand the energy-storing device or sprin which operates the trip member 18. lith the construction shown in the drawing any suitable connection bewas;

" f? operati mechanism and the out' the collapsible-.toggle by any suitable' '15 connectionbetween the .beil crank and the trip member 13 suchas the lost-motion connection shown in the drawing, inl which afstrong spring '28 forming a resilient con'-V `n'ecticlrbetween the beli crank 10 andl the '20 trip member, `and mit enough to overcome thespring 18, is 4connected mt one end to the arin 416 of` `the tripi member- 13 and 'is provided at the other end with a loop- 29 which surrounds a ystud or pin 30 on one` -arm of the bell crank 'lever 10. Theparts *l are so'proportionedthat counterclockwise movement -of thev bell crank lever 10 will straighten out thev collapsible toggle .and aztthesaz'ne time 'exert a` strain on the trip member'which movesy it'about its pivot and puts the spring-'18 under' tension. As a resultof this movement the trip member 13 is' drawn from the tripping position shown in Fig. 4 into its normal position shown .inl

Figc, where energy is storedin the sprin 18, whichis under tension, and the latching:

toggle 19 is'overset to holdthe trip member 13 stationary, while the collapsible toggle is overset to' form' a rigid connc'ctionbetween 40 the' operating handle andthe actuating 'rods 6 of' the switchl mechanism. The resilient connection' between :the operating handle and the trip member 'is .preferably so proportioned that the trip memberis set inl-'normalt position by the 'time/the operating `mechanism has 'made -onl a part ofl the' movement necessary to straighten out the collapsibletoggl'eand further movement of the: operating mechanism 'merely vstretches the:

spring 28 andleavingthetrip member 13 operating mechanism need not necessarily bear a very accurate relation to the movement 4of 'the trip member, as would be .the

case if the connectionbetween the operating 4v155 mechanism and the trip member were ri i Movement of the operating handle to c ose the circuit breaker causes the bell crank lever 10 to turn about its pivot in a clock- `wise direction, thereby causing the pin 30- to travel along the loop 29 ltoward lthe spring 28 and leaving the trip member 13 free to swing up into tripping position if the latching toggle 19 is broken.

The operation of the device is as follows:

- When the circuit breaker is closed, as shown fwhi L When the collapsib `circuit breaker opens automatically and the in Fig. 1, the partsibf the tripping mechanism are in the positionshown in Fig. 2, with' the spring 18 to. throw. the tri memberopinto engagement with, the co1 atpsible toggle, this tendency ,being resiste by .the .overset latching toggle 19, which holds the trip .member stationary. If the current in thecircuiit exceedsa predetermined amount the bolt 20 is. lifted and breaks the latching toggle, whereu nthe trip member 13 is free to swin a ut its pivot as the spring 18. contracts.. movement is not' resisted by the spring 28, .owing to the lost-motion. connection ybetween the lspringand the bell crank lever .10, .while the lost motion between'the arm 14 of, the trip sa member 13. and the colla ible-toggle permitsthetrip member to. eliveragainst' the colla sible toggle a. hea hammer .blow ci; will break the tpgg e even though. a reat strainis exerted upon it bythe springs e toggle breaks, ,the

parts assume the position shown in. Fig.l 4. To close the circuit breaker the o ratin handle is moved to rotate vthe belcran lever ..10 inl a, counterclockwise direction, thereby straightenin 'out the -collapsible toggleand causi ,t spring28 to rotate the trip membera ut lits ivotmgainst the .95 tension of the spring 18, w ereby energy .is stored in the spring... As the trip member, is drawn into. normal posi-tion the .latching toggle 19 is overset and thetrip member, -is then' held stationary.: 4Au the Voperatin handle is moved in theothei :direction and the bellrcrank lever 10 rotates4 in. the clockwise direction, the overseticollapsible toggle forms a positive connection betweenthe operating handle vand the actuating rods 6, while the tripping vmechanism is set and ready to break the collapsible toggle as soon as the Vcontacts engageif there, is an overload on the circuit to cause the trip coil to break the bitching toggle, 19.v

My invention may be embodied. mman other formsA than that shown anddescribe and I, therefore, do not wishV tobe restricted to the precise arrangement disclosed, but intendto v'cover by the appended claims all 115 changes and modifications within the spirit and scope of my invention. A' p What I claim as new and desire-.to secure by Letters Patent of the United States, is,

1. In an automatic. switch or circuit breaker, thel combination with switch operating mechanism and restraining means for holding the switch closed,.of trip mechanism comprising a trip member` biasedH by stored energy to move from normal position to tripping position and thereby en age said restraining means to trip the switc, and a resilient connection between said member and saidmechanism whereby said member is reset in normal position by the movement ot said o erating mechanism incident to closing oi: the switch.

2. In -an automatic switch or circuit breaker, the combination with switch operatin mechanism and restraining means for hol ing the switch closed, of a trip member biased by stored energy to-move `rom normal position to tripping position and thereby actuate said restraining means to trip the switch, a resilient connection between said member and said mechanism whereby said member is reset in the normal position by 'the movement of said operat-in mechanism incidentto the` closing of t e switch, and electroresponsive means for controlling the movement of said trip member from normal position to tripping position.

3. In an automatic non-closable circuit breaker having separable contacts, the combination with an operatin member and a normally ositive collapsib e connection between sai member and'said contacts, said connection being set in non-collapsed position by movement of said member in one direction, whereby movement of said member in the other direction actuates said contacts, of a trip member for collapsing said connection, an energy-storing operating device for said trip member, and a resilient connection between said operating member and said trip member whereby said operating member during its movement to set said connection in non-collapsed position stores energy in said operating device. v

4. In an automatic non-closable circuit breaker having separable contacts, the combination with operating mechanism for the contacts comprising a normally positive collapsible connection, of a tri member biased by stored energy to move trom the normal position to tripping position to collapse said connection, and a resilient connection wherethe '- by said operating mechanism during its movement to set said collapsible connection in non-collapsed position sets s aid trip member in normal position and thereby stores energy for moving said trip member into tripping position.

5. An automatic non closable circuitbreaker comprising separable contacts, an"

operating handle, a collapsiblev toggle for connecting said 4handle and said contacts, a trip member operated by stored energy to collapse said toggle, an energy-storing operating device `for said trip member and means whereby the movement of said operating.

handle to straighten said toggle stores energy in said operating device.

6; An' automatic non closable circuit senseo connecting said handle and said contacts, a

trip member for collapsing said toggle, a

spring for moving said trip member into tripping position, means whereby said operating handle durng its movement to straighten said toggle places said spring under strain and thereby stores energy for operating said trip member, latching means for holding said member against the strain of said spring, and an electroresponsive device or controlling said latching means.

7. In an automatic non closable circuit breaker having separable contacts, the combination with operating mechanism for the contacts comprising a normally positive collapsible connection, of a trip member arranged to collapse said connection and thereby separate the contacts, a spring connected to said member to move it into tripping position, latching means for holding said member in normal position against the strain of said spring, electroresponsive means for causing said latching means to release said member, and a lost motion connection between said trip member and said operating mechanism whereby when said circuit breaker is open said operating mechanism moves said member into normal position and strains said spring and When the circuit breaker is closed said mechanism leaves said-member free to move when released.

8. An automatic non closable circuit breaker comprising separable contacts, an operating handle, a collapsible toggle for connect-ing said handle and said contacts, a pivoted trip lever mounted to strike and collapse said toggle, a spring arranged to throw said trip lever against said toggle, a latching toggle for locking said trip lever in normal position, electroresponsive means for controlling said latching toggle, and a lost motion connection between said trip lever` and said operating handle whereby said handle in straightening said collapsible toggle sets said member in normal position with said spring under strain and in closing the circuit breaker leaves said trip lever free to collapse said toggle when said trip lever is released.

In witness whereof, I have hereunto set my hand this 9th day of September, 1908.

CHARLES T. HENTS CHEL.

Witnesses:

BENJAMIN IB. HULL, MARGARET E. lllooLLnY.

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