US2663774A - Electromagnetic trip circuit breaker - Google Patents

Description

Dec. 22, 1953 J. B. MaGNElLL ET AL ELECTROMAGNEIIC TRIP CIRCUIT BREAKER Filed July 22, 195o 4 Sheets-Sheet l John B. MocNeiH 8 Hurry J. Lingul, BY/

ATTbRNE Dec. 22, 1953 J. B. MaoNElLL ET AL 2,663,774

ELECTROMAGNETIC TRIP CIRCUIT BREAKER Filed July 22, 1950 4 Sheets-Shea?l 2 WITNESSES: {NVENTORS John BA MocNeill 8\ Hurry J. Lingul.

xi" TORNEY d Dec. 22, 1953 J. B. MaCNElLL ET AL ELECTROMAGNETIC TRIP CIRCUIT BREAKER Filed July 22, 1950 4 Sheets-Sheet 3 2o? 2es '7' 297 2|5 |99 '7| 2|9 205 3||- |95 |97 3131 i 22| 20| os 225 Flg. 5. 30| 223 F|g-6- .WTNESSES: INVENTORS John B4 MocNeH 8| Harry d. Lingul. mg um! ATTORNE J. B. MaCNEILL ET AL 2,663,774 ELECTROMAGNETIC TRIP CIRCUIT BREAKER 4 SI'Ieecs-Sheel 4 S R m .0,205 E .WEF O 3 1 O 0 2 T. 5 6 3 wl 6 .o 2 I N .b I 6 W f f 7 1 I |1l l|| II.. I. |.I I 6 o m l f w g 9 v 3| s .cn m y e 2 2 99 H l e 0 m l I 2 2 22.7 n .I 6 V. e T .T 9 2 9 l S D f 2 O n S O l f2 .W e e U O $5 7 d m m w I O RDV W. A n xnlv W 2 2 V. .u I. Mw I U .m s 3 9 9 n l 1 n n n 5 lh 2 2 I e S S O 3 n 4 5 5 3 m I 7. l 4 2 3 Q H V 2 3 3 m T .m .T H 3 m. 0 5 7 O R 208 7. 3 4 L .1.V..4|22 5 7 2 2 O m .m mm 8 2 O .n.le 2 0C S TD 0 7 f O w 0 D. E u w 4 6 7 5 U .m 5 5 Oe h Ti 2 2 D. k O C S D. 000009 U .mw 4r 80246 P e P 46789 k P 7 sn oicmwm u D Pn we I T.| 7 e m P 33 3 g w1 em 3 I B ekn ml 3 F mC@ .IS .Til 02468n|v I TU nd gev. 5 Dim .la o nmmnIhIF.. T m nd mA -o um @www y w A www mA m s 0 O 0 O M O e d S .l l W 6 7 8 9 2 LD A N I 7 P 2 O O O O O O0 O 0 64 2 I 64 2 I 64 2 l W 4 0 2 O Mw w m 0 64 2 l O0. O 0 I Dec. 22, 1953 Filed July 22, 195o m-UCCOww E @E F.

TTORNEY Fig.9.

4valve means to admit Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE ELECTROMAGNETIC TRIP CIRCUIT BREAKER John B. MacNeill and Harry J. Lingal, Pittsburgh,

Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania f Application July 22, 1950, Serial No. 175,373

rents above said. predetermined valueor short cirmiits.Y i A `Another' object of the invention is to providea circuit breaker having av trip device einbodying a time-delay device of the uid dashpot Vtype in which time delays or" different duration are effected in the operation ol theV trip device'in different ranges oi overload"currents by admitting iuiol to the dashpot at different rates. Another object oi the invention is to provide a circuit breaker having electroresponsivetrip device embodying a novel tiinedelay device oi the iuid dashpot type in which time delays 'of dii'ierent `durations are effected inY the operation of the trip device b the operation of a single valve means to admit :luid to the dashpot at different rates. H

A further object of inve onis to provide 'reuit breaker having an electroresponsivetrip device embodying a novel Vtirne-delay device' of 'the luid dashpot type in which time delays o different durations are eected in the operation oi the trip device by the operation of a single tothe dashpot at different rates, the vaive ineans being selectively operated eieotroinagnetically in response to overload currents of different magnitudes.

Another object oi the invention is to provide a circuit breaker with an electroresponsive'trip device embodying a novel ine-delay means of the fluid dashpot type in which time delays of different durations are effected in theoperation of the trip device.A by the operation of a single valve ineens to admit fluid to the dashpotat different the valve sans being operative by a. plurality of armatures seiectively responsive to overload currents o different magnitudes.

The novei features that are considered characteristic of the invention are set forth in the appended claims. The invention itself, however, both as to structure and. operation, together with additional and advantages thereof, will be best understood from the following detailed response to overload currents of yintermediate value below a predetermined value and instantaneously in response to overload eur- -19 Claims. (Cl. ZOO-408) -cured'to a metal supporti pivotally mounted Toy means oi' a pivot pin on e 2 description oi' a preferred einbodiiae -t tlereoi, when read in connection with the accompanying drawings.

In said drawings:

iiguie l is an elevational View', pa tion, of a circuit breaker embodying of the invention;

Fig. 2 is an enlarc'en sectional view tai; stantiallv along th .av in seothe principles is a sectional plan view evice taken substantie. ly

oi tlie timealong lin 3 and looking in the direction i c. arrows;

ri 5 is an elevational seeti vie taken substantially along line "iT-V or s, e, ng

in the direction oi' the and snowing the adjusting means for the short-tiinedelay ar1nature;

Fig. 6 is an elevational sectional substantially on line Vl-V oi' eig. e, looking in the direction of the "ows and @lowing the control valve for the time-delay device together with the adjusting means therefor; Fig. 7 is an elevational view oi tile time-delay device showing' the scale plate and. the several adjusting knobs;

Fig. 8 is a schematic vieiv of the trip :levi-2e illustrating the several adjusting ineens for tne tiineudelay device; and

."ig. 9 is a schematic diagram of adjustment oi' the trip dev' Referring to Fig. i of the breaker includes a plarolity o comprising a Contact sAv u orally at Ii and an ove cated generally at i3. Contact structure and the trip device for each pole unit are nico-,nf a separate insulating base which i' view taken showing the range ig's, trie cir-cuit i oole units each o pole units are alike, only l y pole nin is illustrated `and described The Contact structure if' n main and aroing contacts it and iii botlisecni on the inner end of a terminal conducting 23 and cooperating movable main and arci` g contacts 25 and The movable contacts rigidly secured to a contact-carrying member U-shapecl switch arm which, in turn, is pivotally supported by pivot means 35 on brackets 3l rigidly mounted on the insulating base i5.

The movable contact-carrying member 29 is electrically connected by means oi a fiexibie conductor 39 to the energizing coil of the trip device i3. A spring il compressed between the movable contact-carrying member 29 below its pivot El and the insulating base iii provides contact pre. sure in the closed position of the breaker and also biases the movable contact structure in opening direction. i

The movable Contact structure is normally maintained in the closed position by means of an operating mechanism indicated generally at 1.3 mounted in a U-shaped frame The frame l5 is supported on a platform i? which forms a cross member of a generally U-shaped main bracket com rising a pair of spaced side membersv member 81 on a channel-shaped latch 59 pivot-ed on a pivot pin Sl in the frame d5. A spring 9E serves to bias the latch lever 8l and the latch 89 to their latching positions.

A trip bar 95, extending across all of the poles of the breaker, is rigidlymounted on the righthand end of the channel-shaped latch has insulating brackets el (only one being shown) secured thereto, there being a bracket el for eacipole of the breaker. Each of the brackets u? has a headed screw 9s adiustably mounted thereon for cooperating with the trip device i3 of its associated pole in a manner to be presently described.

mounted in the front piece of the frame de. The

49 rigidly connected at their outer ends by .the Y I cross member or platform ell. rhe platform l extends substantially across the width oi the breaker and the side members 13E are suitably secured to the metal panel l'a' on the outside oi the two outer pole units or" the breaker.

The operating mechanism includes a lever 5i mounted on a pivot pin es members of the frame The lever 5l carries a rod 55 extending across all of the poles of the breaker and is connected by means of insulating connecting members 5l to the pivot pins 3i the free ends of the switch arms 9, for the several poles of the breaker so that upon operation or the rod 55 the movable contacts or" all of the poles move in unison.

An operating linkage comprising toggle links 5S, Si and G3 is provided to releasably hold the lever 5i and consequently the movable contacts in the closed position and to operate the movable contacts to open and closed positions. The toggle link 59 is pivotally connected to the lever 5l by means of a pivot pin 65 and the toggle link 63 is pivoted on a ixed pivot i?? supported in the frame Ll'i. rhe toggle link @l is pivotally conn nected to the links E15 and respectively, by knee pivot pins 59 and l'i.

The linkage 5G, 5i, comprises two toggles, one or which eil-bi be designated as the tripping toggle and the other t i-'s as the closing toggle. The tripping toggle E3B-5i is normally slightly underset above ay line drawn through the centers of the pivot pins -i and the closing toggle iii-53 is normally underset below a line drawn through the centers of pivot pins Sl-ES. The closing toggle 'S iis normally prevented from collapsing downward by a support member is pivotedon a pivot pin 'E5 supported in the frame d5 and having a shouldered portion engaging under the knee pivot pin li.

The tripping toggle S-Si is normally biased in a direction to cause its collapse by a component of the force oi the springs fi-l which bias the movable contact structures for the three poles of the breaker in opening direction and bias the connecting member 5l toward the left (Fig. l). The tripping toggle iis-Gl is normally prevented from collapsing by means of a main latch member Vi pivoted on the pin e.; connected by means of a link 'i9 to the knee pin $59 of the tripping toggle.

The main latch member 'il is held in latching position by an intermediate latch lever si pivoted on the pin l5. The intermediate latch lever 8| carries at its upper end a latch roller E3 engaging the main latch 'il and at its lower end has a latching portion Se normally engaging a latch supported in the handle is not shown in the drawings but is rigidly secured to the outer end of the sha-it le?, and biased in both directions to a central position in a well-known manner by means oi a spring I'i.

Rotation of the handle shaft m3 in tripping direction causes the cam member le! to engage and actuate the latch member 89 in counterclock- Wise or unlatching direction to unlatch the intenmediate latch levcr El, which, in turn, releases the main latch il. This permits the tripping toggle FaS-l to collapse upwardly to eect opening of the breaker contacts. During the collapse of the tripping toggle, a portion |69 of the toggle link 8| engages and actuates the support member i3 to a non-supporting position, thereby freeing the closing toggle iii-$35. The closing toggle thereupon collapses downwardly and during its collapse resets and relatches the tripping toggle bil- El.

The breaker contacts may now be operated to the closed position by rotating the shaft its and the cam IEM in the direction opposite to the tripping direction. This causes the cam ll to engage a projection i i i on the closing toggle link 53 and moves this link counterclockwise about its pivot el until the support member 'i3 resumes its supporting position below the knee pivot pin ll. During the closing operation, the link 'i9 prevents collapse of the tripping toggle e-Si which acts as a thrust transmitting means and moves the movable contact structure to the closed position.

The breaker is automatically tripped open by operation of the trip device i3 for any pole of the breaker. The trip device includes generally a tripping electromagnet H3 (Figs. 1 and 3) and a time-delay device IE5. The tripping magnet H3 includes a C-shaped magnet yoke H7. The ends 23 of the magnet yoke form mounting feet and are `drilled and tapped to receive mounting bolts 25 and I2? as shown in Fig. l.

The upper end of a stationary magnet core 129 (Fig. 3) is provided with an internal "bread which cooperates with a threaded nipple 431i disposed in an opening in the magnet yoke to rigidly secure the stationary core 29 to the magnet yoke.

Surrounding the stationary core member ll is an insulating tube E38 around which is disposed the energizing coil lill of the magnet.

As shown in Fig. l, the bolt 25 which secures the upper end of the magnet yoke to the base i5 also secures the flexible conductor 3e to the upper turn of the coil l. The lower turn of the coil lill is formed into a lug iii-3 which, together with the inner end lli5 of a terminal IM, is secured to the base l5 by means of a bolt leg- A tubular member l5! (Fig. 3) of magnetic material is mounted in an opening in the lower portion of the magnetic yoke i1 'l and extends upwardly within the insulating tube i3d. Disposed within the tubular member 151 is a movable core member or armature indicated generally at 153 comprisino an upper portion 155 and a tubular lower portion i5?. The armature |53 is provided with a central opening through which extends a trip rod iti extending axially through the movable armature an opening in the stationary core member and an opening in the nipple 131. A spring E53 coiled about the trip rod 151 is compressed between a counterbore in the armature 53 and a collar 55S which bears against a spring clip ide seated in an annular groove in the trip rod itl.

The trip rod |61 is moved upwardly to trip the breaker under the control of the time-delay device li which comprises, generally, a movable abutment or iieXible diaphragm I'l (Fig. 3) cooperating with the lower ond of the trip rod and a valve element for admitting to the space below the movable abutment or diaphragm at various rates to provide diierent amounts of time delay. The flexible diaphragm is disposed in a chamber formed in an upper housing member 1'!! and a lower housing member 113, bother said housing members being formed of molded insui e material. rEhe outer edge of the diaphragm together with a sealing gasket is clamped between the housing members to form an air- *i t seal. The housing members lit-|73 are .sc-cured together rigidly secured to the magyoke l l'i by means of bolts (not shown). The central portion oi the diaphragm iii? is clamped between upper and lower clamp members 1lb and ii, respectively, the upper clamp 1i9 having an annular projection 53 extending downwardly through an opening in the lower clamp |31 and formed over against the lower face of the latter to form an airtight seal.

Secured to the lower end of the trip rod 16| is a sleeve l' provided with a flange 85 to the upper face of which is suitably attached a facing 239 of a tough resilient material. The sleeve |85 is disposed in a central opening |853 in the upper clamp member H9. An annular valve seat |92 ormed on the clamp member 119 about the openrg is provided to cooperate with the facing to close the opening 18|) upon upward or tripping movement of the trip rod |1. The lower portion lidi of the movable armature extends downwardly through opening in the upper wall of the housing member 1l1 and is normally seated on the upper face of the upper clamp member lli? surrounding the opening |90.

Disposed in the space above the diaphragm 161 is a ring Stb having an inwardly extending flange Disposed between the flange 19". and the upper wail its of the housing member Ill is a iilter 2&1 for ltering any air that may be drawn into the chamber through an opening 2553 (Fig. (i) formed in the wall 1529 of Ithe housing. Ordinarily in the operation or the time-delay device, air is merely transferred from the space above the diaphragm to the space below the diaphragm. However, due to variations in temperature of the surrounding atmosphere, the device may breathe air onto and out of the chamber. The lter ttl is provided to prevent foreign matter from being drawn into the chamber by such breathing Since the spaces above and below the diaphragrn lo? are sealed oir` from each other and the space above the diaphragm is at atmospherlc pressure, any force tending to raise the trip rod |51 will be restrained by the partial vacuum be low the diaphragm. In order to control the rate of tripping movement of the trip rod 16 l, a single valve device indicated generally at 285 (Fig. 6) is provided to admit air to the space below the diaphragm le? at varying rates to provide long time delay and short time delay in the tripping movement of the trip rod and also substantially instantaneous tripping movement of the trip rod 16|.

.The valve device 205 (Fig. 6) includes a valve member 2o? having a tapered valve 2de at the lower end thereoic cooperating with a tapered valve seat 211 formed in the housing member 1li. The valve member 29'.' is disposed for sliding movementu in a metal thimble inserted in an opening 2 1 in the housing member 111 and having an enlarged portion 21? threadedly engaging the housing member. A spring 219 compressed between the valve 239 and thebottomof the thimble 253 biases the valve in closing direction. A passage in the housing member 171 communicates the space above the diaphragm 151 to the opening 215 above the valve 289, and a passage 222 communicates the space below the diaphragm to the space below the valve 209. Thus, the valve 2de-11 controls the passages 221--223 which communicate the spaces above and below the diaphragm 1b?. Openings 225 (only one being shown) are provided in the ring 95 to permit fiow of air from the space inside the ring to the passage 221, the cross-sectional area of the openings 225 being at least equal to the cross-sectional area of the passages 221-223 at the narrowest point.

On long-time-delay tripping operations, in respense to low overload currents, the valve member is not moved but is normally maintained in slightly opened position by an adjusting device (to be described later) to admit air below the diaphragm for controlling the rate or tripping movement of the trip rod 1i`i1 on such operation. Upon the occurrence of an overload current in the higher range of overload currents below a predetermined value, the valve 291 is opened a predetermined amount by means of a secondary or short-time-delay armature 221 (Figs. 4 and 5). On overload current above the predetermined value or on short circuit currents an instantaneous armature 225i (Figs. i and 5) is actuated to move the valve 2t? to its full open position to permit substantially instantaneous tripping movement of the trip rod Iel.

The short-time-delay armature 22? is pivotally supported at its right-hand end (Figs. 4 and 5) by means of projections 234 which t in openings in the right-hand wall or the housing member i. The instantaneous armature 22:5 is similarly supported by projection 33 thereon.

The armature 229 (Figs. 2 and Ll) is biased to unattraot-ed position by means of a spring 235 having one end attached to the armature and the other end attached to an adjustable member 23'! threadedly engaging an adjusting screw The member 2s? is provided with a narrow pointer 2LH which projects through a vertical slot 243 in a scale plate 245 (see also Fig. '7). The adjusting screw 239 suitably secured to an adjusting knob 247 (Figs. 2 and '7) journaled in an opening in the housing member H3. Rotation of the knob 247 and the screw 239 moves the member 23? up or down, depending on the direction of rotation of the knob, and varies the tension of the spring 235. This varies the pick-up point, that is, the minimum value of the overload current required to operate the armature 229.

A similar adjustment is provided for the shorttime-delay armature 221 (Figs. Vl and 5). A spring 2tlg, one end of which is attached to the armature 221, has its other end attached to an adjustable member 25l (Fig. 4) similar to the menber v231. The member 25I threadedly engages an adjusting screw 253 journaled in an opening in the housing member H3 and is provided with a knob 255 (Fig. 7) for rotating the screw. The member 25i is also provided with va pointer 251 which projects through a vertical slot 259 in the scale plate 265. Rotation of the screw 253 will move the member25l up ordown, depending on the direction of rotation, to vary the minimum overload current requiredto `actuate the short-time-delay armature 221.

An opening 25! (Fig. 3) in the magnet yoke i I1 provides an air gap for the magnetic circuit through the armature 229, and a similar opening (not shown) provides an air gap for the magnetic circuit through the armature 221. As shown in Fig. each oi the armatures 221 and 229 is provided with a recess 253, and each armature is adapted to engage under a head 255 on the upper end of the valve member 251 upon actuation of the armatures to effect opening movement ofthe valve member 251 and opening of the valve 259- 2ll (ig. 6). This opens the previously described communication 22 4 223 (Fig. 6) and permits air to pass from the space above the dia'- phragm 51 to the space below the diaphragm to control the tripping movement of the trip rod i5 I. The rate oi iiow oi air to the space below the diaphragm and consequently the rate of tripping movement o the trip rod is controlled by the amount of opening oi the valve Z55-2i I.

The extent of opening movement of the valve member .251 is adjustably controlled by means of an S-shaped stop member 261 (Figs. 4 and 5) to thereby determine the amount of time delay provided on short-time-delay tripping operations. The upper portion 255 of the S-shaped member comprises an adjustable stop and is disposed in the path of valve-opening movement of the upturned end of the armature 221 to be engaged thereby and thus limit upward movement of the armature and limit the extent of opening of the valve 251. The center cross member 21! of the S-shaped member 251 has threadedopening therein which is engaged by an adjusting screw 213, so that upon rotation of the screw 213 the Seshaped member 251 will be moved up or down, K

depending on the direction of rotation, to provide for greater or lesser opening movement of the armature 221 and, hence, greater orlesser opening movement of the valve 251.

The lower end or the adjusting screw 213 is rigidly xed to a shait 215 rotatable in an opening in the lower housing member |13, and the shaft is provided with an integral knob 211.

In order to give a visual indication of the setting of the adjustable stop 255 and, hence, of the short-time-delay setting, there is provided a pointer 215 (Fig. 5). The pointer is U-shaped and the two legs (only one being shown) thereof straddle the adjusting screw 213 and engage in notches 25| (only one being shown) on opposite sides-oi the adjustable stop member 251. The pointer 215 is biased downwardly by means of a spring 253 and has a reduced portion 2235 extending through a slot 281 in the scale plate 245 to indicate the setting of the adjustable stop 259 and, therefore,the amount of time delay provided for the short-time-delay operation.

The valve 201 isadjustable to determine the amount of long time delay provided in the operation of the trip device by means or an adjustable S-shaped stop member 235 (Fig. 6). The stop member 285 is provided with a horizontally disposed stop 29| which is biiurcated to embrace the valve member 251. A collar .293 on the valve member 251 rests on top of the member 29| to determine the amount of opening of the valve 255- 2Il and, therefora'the amount of long time dem lay. A cross member 295 on .the stop member 289 is provided with a threaded opening which is engaged by an adjusting screw 251 having a shaft 292) at its lower end rotatable in an opening in the housing member 113. The shaft 259 has xed thereto a manual knob Sill for rotating the screw 251 and thereby moves the adjustable stop member up or down depending on the direction of ro*- tation of the screw. Movement of the adjustable stop varies the opening or" the valve 265-2 I I and thereby varies the amount oi longtime delay.

The .long-time-delay adjusting device is provided with a pointer 353 similar to the pointer 219 (Fig. 5) for the short-time-delay adjustment. The pointer 353 is U-shaped and straddles the adjusting screw 251 and the S-shaped stop member 289. The two legs (only one being shown) or" the pointer engage in notches 555 in opposite sides of the stop member and pivotally engage a shoulder 551 on the housing member I1I. The pointer 353 is biased downwardly by a spring 359 and has a reduced portion 5I I projecting through a slot EIS in the scale plate 2ll5 to indicate the setting of the long-,time-delay device.

An adjustment is provided for varying the longtime-delay pick-up point, that is, thevminimum overload current required to actuate the main armature I53. This adjustment comprises a member @I5 (Figs. 3 and 4) having one end biurcated and the legs 3|1 thereoi pivotally supported in openings tig (Fig. 3) of the housing member I1I. Theright-hand end of the member 3I5 is U-shaped and has opposed inwardlyrextending projections 321 engaging an annular groove 323 in the lower portion 51 of the armature i555. The projections 32| are biased by means of a spring 325 against the lower wall or" the groove 523, thus biasing the armature against attraction. The spring 325 has one end hooked into an opening in the member SI5 and the other end attached to an adjustable member 321 threadedly engaging an adjusting screw 329. The adjusting screw 329 is secured to a shaft BSI rotatably supported in the housing member I13 and having a manual knob 553 secured thereto bearing against the bottom of the housing member 13. rlhe adjustable member 521 is provided with a reduced portion 335 extending through a slot 331 in the scale plate 245 to indicate the setting of the long-time-delay pick-up. Botationof the screw 329 will move the member 321 up or down depending on the direction oi rotation and accordingly vary the tension oi the spring 525 and, hence, the pick-up point of the long-time-delay means. The scale plate 2d5 bears indicia adjacent the several pointers, as shown in Fig. '1, to indicate the settings of the several adjustments of the trip device.

The trip device functions with time delays of diierent duration in two distinct ranges of overcurrents below a predetermined magnitude and instantaneously in response to overcurrents above the predetermined magnitude, or in response to short circuit currents. The ranges or" overcurrents may be arbitrarily defined as, for example, a low range up to 500% or 600% ci normal rated current, an intermediate range between 500% or 600% and 1000% of normal rated current, and instantaneous 1000% or more or" normal rated current.

Assuming an overcurrent within the low range ci overcurrents, the trip device, with particular reference to Fig. 8, will operate as follows: Upon the occurrence of an overcurrent in the low range of overcurrents, the electromagnet becomes energized and attracts the armature |53 upwardly. The armature acts through the spring E53 and the collar |59 to produce an upward thrust on the trip rod lei, the movement of the trip red being retarded by the partial vacuum below the diaphragm or movable abutment lill. The initial upward movement of the trip rod causes the valve facing |89 to engage the valve seat |82 on the clamp member 19 to thereby completely seal oli the spaces above and below the diaphragm |61.

The trip rod itl moves slowly upwardly in tripping direction as air is drawn into the space below the diaphragm through the valve 203-22 until the upper end of the trip rod engages the headed screw 99 (Fig. l) and actuates the latch mechanism to eiect tripping of the breaker in the previously described manner. The time delay provided by the long-tirne-delay setting of the valve Zilli-2H is in the order oi seconds and may be varied by adjusting the valve 2te-2H as previously set forth.

As soon as the breaker contacts are opened, the tripping magnet |53 is deenergized and the armature |53. and the trip rod l! are restored by the spring 325 and the force of gravity to their Fig. 3 positions. Immediately upon deenergization of the tripping magnet H3, the armature S53 drops into engagement with the upper iace of the clamp member |19. The lower end of the tubular lower portion I5? of the armature member |53 also engages the sleeve |85 and opens the valve Ess- |82 permitting high-speed equalization of air pressure above and below the diaphragm it? through the opening |96 in the clamp member ils and through openings 33S in the lower of the armature member I5? to thereby eiect high-speed return of the parts to their normal lower positions as shown in Fig. 3.

'Upon the occurrence of an overcurrent in the intermediate range of over-currents, the electromagnet i |53 is energized sufficiently to attract the shcrt-time-delay armature 221 (Figs. and 5) upwardly against the adjustable stop opening the valve 28g-2H (Fig. G) an amount determined by the adjustment of the stop 2st. This admits air to the space below the diaill at a higher rate and provides a relatively short time delay in the order of altenating-current cycles in the operation of the trip rod.

Energization of the tripping magnet i E3 in response to overcurrents in the intermediate range is not sufficient to attract the armature 225; however, upon the occurrence of an overcurrent of l090% or more of rated current or a short circuit current, both the sliort-time-delay armaY ture Eil and the instantaneous armature 22 are attracted upwardly and move the valve member to its full extent, thus fully opening the valve 2fle-2i i thereby admitting air to the space below the diaphragm itl at arate to permit subnfl Ol) l0 stantially instantaneous tripping movement of the trip rod |6|.

On short-time-delay and instantaneous tripping operations, the spring |63 limits the force applied by the moving armature i 53 to the timedelay device. On such operations the armature |53 is attracted` immediately against the Xed core member i 2e comprising the spring i53 which thus supplies the force necessary to actuate the trip rod 56| the pull exerted on the timedelay device is limited to the maximum force exerted by the spring |63 when it is compressed. This prevents damage to the time-delay device and provides a uniform pull on the time-delay device.

The circuit breaker is well adapted for the protection oi distribution systems. Such systems are usually protected by a series of breakers including generator breakers, bus tie-in breakers, feeder breakers and load breakers. The circuit breakers of such systems are usually adjusted for selective tripping; that is, if a fault should occur' at any point in the system, the breaker nearest the fault and on the generator side or" the fault should open to clear the fault condition.

The time-current requirement ci the tripping device varies with the position of the breaker in the selective system for which reason a trip device providing a wide range of adjustment is essential. As shown in 9, the trip device is capable of a wide range or" adjustments. There ilve separate adjusting devices ll located outside the device for ease oi" accessibility. By way of example of the ran 'es of adjustments, the following have been arbitrarily selected as illustrative ci' ranges of adjustments:

l. Range of long-time-delay pick-up, from to 160% of coil rating.

2. Range of long time delay, from 23 to 85 seconds.

Range of short-time-delay pick-up 509% te 10005727 of coil rating.

e. Range of short time delay, from fi to 30 alternating-current cycles.

5. Range of instantaneous .000% to 1.500% of coil rating.

9 graphically illustrates the ranges of the everal adjustments of the trip device. Along the left-hand edge of S is indicated the time in seconds. The percentage oi coil rating is shown along the bottom, and the time in alternating-current cycles based on Sil-cycle frequency is shown along the right-hand edge of Fig. 9. Curve A represents the minimum settings and curve B, the maximum settings. By adjusting the snob (Figs. 3, and 8) the long-timedelay pick-up may be adjusted to piel: up at any point in the band of adjustments defined by curves .ft-B as at C, that is, for example, between 80% and 160% of coil rating. Adjusting the knob 35| (Figs. d, 7 and 8) which controls the initial opening of the valve 26d-2| i varies the amount of long delay between 23 and 8S seconds as indicated at D in Fig. 9. As indicated at E (Fig. 9) the short-ti.` e-delay pick-up may be set to piclc between 500% and ci coil rating. This is effected by adjusting the knob '255 (Figs 7 8). amount of short time delay may' be varied between 4 and 30 cycles, as indicated at l, by adjusting the knob 2li (Figs. 5, 'Z and SL Finally the instantaneois pick-up point may be varied between 30111074, 150075 of coil rating, as indicated at Cr in Fig. 3 by adjusting the knob 242i (Figs-U from pirfi-up, from Til and 8 which controls the tension ofthe biasing .for t e instantaneous armature 229. ci these adjustments may be easily made by merely turning the adjusting linob associated with. particular adjusting device previously described. The adiustments are independent of each other and, as shown in Fig. '7, all of the adjusting irnobs are conveniently located.

The complete adjustability of trip device eliminates the necessity of increasing band Width of adjustments to compensate for manufacturing variations different coil ratings. |'She variations of tripping time due to temperature changes is negligible. This is made possible by the use ci air as the delaying medium. ri`he tripping tz' depends on the velocity of air flow through the valve oriiice and is not affected by changes inair density.

{ai/'ing described the invention in accordance with the patent statutes, it is to be understood that various changes modifications may be made in the structural details and combination of elements disclosed Without departing from some oi the essential features of the invention.

W claim as our invention:

1. En an electromagnetic trip device including a trip rod movable to effect a tripping operation, said trip device comprising an energizing Winding, an armature operable upon energization of said winding to move said trip rod, a time-delay element for retarding tripping movement of said trip rod having a chamber, a normally open valve for admitting nuid to said chamber at a predetermined rate to eiect a relatively long time delay in the tripping movement of said trip rod, and a second armature operable by energicationY of said Winding in response to cetain abnormal circuit conditions to actuate said valve and increase the rate of' admission of fluid to said chamber to eiiect a relatively short time delay in the tripping movement of said trip rod.

2. In a circuit breaker having relatively movable contact means and operating means therefor, the combination of a trip member operable to eect a tripping operation, an electromagnetic trip device comprising an energizing Winding, an armature operable upon energization of said winding in response to overload currents to operate said trip member, a time-delay element for retarding tripping operation of said trip member having a chamber, a valve having an initial open position for admitting fluid to said chamber at a predetermined rate to effect a relatively long time delay in the tripping` operation or said trip member, a valve-operating armature operable upon energization of said Winding in response to predetermined abnormal circuit conditions to actuate said valve and increase the rate oi admission of iiuid to said chamber to effect a relatively short time delay in the operation of said trip member, and adjusting means for adjusting the initial open position oi said valve to vary the amount of time delay provided by said initial open position of said valve.

3. ln a circuit breaker having relatively movable contact means and operating means therefor, the combination of a trip member operable to effect a tripping operation, an electromagnetic trip device comprising an energizing winding, an armature operable upon. energization or said winding in response to overload currents to opcrate said trip member, a time-delay element for retarding tripping operation of said trip member having a chamber, a valve having an initial open position for admitting fluid to said chamber ata predetermined ratev to4 effect a relativelylong timedelay in the tripping operation ofV said trip member, a valve-operating amature operable upon energization of said winding in response to predetermined abnormal circuit conditions to actuate said valve and increase the rate of admission of iiuid to' said chamber to eiTect a relatively short time delay in the operation of said trip member, and adjusting means for adjusting the initial open position of said valve to vary the amount of time delay provided by said initial open position oi said valve, an adjustable stop for limiting the opening movement of said valve-operating armature, and adjusting. means for varying the setting of said adjustable stop to vary the extent or" opening of. said valve and the amount oi said short time delay;

4. In-a circuitY breaker having relatively mov"- able contacts and operating means therefor, the

combination of a trip rod, an electromagnetic trip device comprising an energizing Winding, an armature operable upon encrgiaation of said Winding in response to overload currents to operate said trip rod, a time-delay element for. retarding tripping operation oi said trip rod including a chamber, a valve having,` an initial open position for admitting fluid to said chamber at a predetermined rate to eiect a relatively long time delay in the operation of said trip rod, a first valve-operating'armature operable upon energization of said winding in response to overload currents below a predetermined value to actuate said valve' to predetermined distance in opening direction to increase the rate of admission of fluid to said chamber to thereby effect a relatively short time. delay inthe operation ci said trip rod, and a second valve-operating armature operable upon energiaation or said Winding in response' to overload currents above said predetermined value to actuate said valve to the full open position and permit instantaneous operation of said triprod.

5. In: an electromagnetic trip device comprising a trip member, an energizing winding, an armature operable lupon energication of said Winding to actuate rip member, a timedelay element comprising a movable abutment for retarding tripping movement oi said trip member, means denning a chamber, a valve for admitting iuid to said chamber, a first valveoperating armature operable upon energization of said Winding in response to overload currents below a predetermined value to open said valve a predetermined distance to admit fluid to said chamber at a predetermined rate to retard tripping movement of said trip member, and a second valve-operating armature operable upon energization of said Winding in response to overload currents above said predetermined value to actuate said valve to theA full open position to permit instantaneous operation of said trip member.

6. In an electromagnetic trip device comprising a trip member, an energizing Winding, an armature operable upon energization of said winding to actuate said trip member, a timedelay element comprising a movable abutment for retarding tripping movement of said trip member, means defining a chamber, a valve for admitting fluid to said chamber, a first valveoperatingv armature operable upon energization of said winding in response to overload currents below a predetermined value to ope-n said valve a predetermined distance to admit fluid to said chamber at a predetermined rate .to retard tripping movement of said trip member, and a second valve-operating armature operable upon energia/ation of said winding in Vresponse to overload currents above said predetermined value to actuate said valve to the full open position to permit instantaneous operation of said trip member, and adjustable means for varying'the amount of opening of said valve bysaid first valve-oper.- ating armature to vary theamount of time delay.

7. ln an electromagnetic trip device comprising a trip member, .an energizing winding, an armature operable upon .energization of said winding in response to overloadV currents to actuate said trip member, a time-delay device comprising a uid; daslipot for retarding tripping movement of said trip member, asingle value' controlling a passage for admittinguid to's'aid daslipot, a pair'of valve-operating armatures for actuating said valve in opening direction to admit fluid to said dashpot to permit tripping movement of Asaid trip member, means limiting the movement 'of one of said armatures'to thereby limit the amount of opening of said valve When said valve is operated by said one armature to provide a time delay in the tripping movement of said trip member.

8. In an electromagnetic trip device comprising a trip member, an energizing Winding, an armature operable upon energization of said winding in response to overload currents to aetuate said trip member, a time-delay device comprising a fluid dashpot for retarding tripping movement of vsaid trip member, a. single valve controlling apassage for admitting uid to said dashpot, a pair or" valve-operating armatures for actuating said valve in opening` direction to admit iiuid to said dashpot to permitrtripping movement of saidtrip member, means limiting the inovement'ofone of said armatures to thereby limit the amount of opening of said valve when said valve is operated by said one armature to provide a time delay in the tripping movement-of said trip member, and adjusting means for varyingthe amount of opening of said valve by said one armature to thereby vary the amount of time delay.

9. In an electromagnetic trip device comprising a trip member, an energizing Winding, an armature operable upon energization of said Winding in response to overload currents to operate said trip member, a time-delay device com*- prising a fluid dashpot for retarding tripping movement of said trip member, a single valve controlling a. passage for admitting fluid to said daslipot, said valve having a normal partially open position for admitting fluid to said dashpot at a predetermined rate to eiiect a relatively long time delay in tne tripping operation of said trip member, a rst armature operable when said Winding is energizedin response to-overload currents below a predetermined value to actuate said valve to an intermediate open position to increase the flow of uid to said dashpot and thereby eect a relatively snort time delay in the operation of said trip member, and a second armature operable said Winding is energized in response to overload currents above said predetermined value to actuate said valve to a full open position to permit instantaneous operation of said trip member.

l0. in an electromagnetic trip device compris ing a trip member, an energi ing winding, an armature operable upon energization of said winding in response to overload curi-entete operate said tripmember, a time-delay device comprising a fluid daslipot for retarding tripping movement of said trip member, a single valve controlling a passage for admitting to said daslipot, said vave having a normal partially open position for ad; tting to said dashpot at a predetermined rate to effect a relatively long time delay in the trippmg o eration of said trip member, a iirst armature ie when said winding is energized in response to overload currents belov.7 a predetermined value to actuate said valve to an intcrr colate open position to increase the new oi uid to said daslipot and thereby effect a relatively snort time deiay in the operation of said trip member, and a second armature operable when s winding energized in response to overload currents above predetermined value to actuate ve to a full open position to permit instany of said trip member, means for selectiveli7 ely mova- A pans the ein a partially o tion to admit fiuid to said daslipo'- determined rate to effect a long ti" the order or seconds in the oper trip means, a rsty armature eperab electroresponsive means is energ to overload currents below a pred to aetuate said valve and cause sani t v crease the rate of admission of iiuid to s pot to effect a short time delai" in the order of alternating-current cycles in the operation of said trip means, and a second armature operable When said electroresponsive .e s is energized in response to overload currents e tov-e predetermined value to aetuate sa re to full or position to admit iuid to said daslipot rate to permit instantaneous operation of trip means.

l2. In a circuit breaker leavin@ rela tire-1y movi.- ble contact means and opereL therefor, the combination of t i sponsive means for operatm time-deiaj; means comprising a retarding tripping operation of sa a valve having an initial oper pos erable to intermediate and full ope admit fluid to said daslipeL means for tably detei ing opening of sarl valve in said mediate position, ld valve in position admitting .Quid to said determined rate eieet a rele' delay in the operation of armature operable when said means is ener ired respon rents below a pret said valve to said interni increase the rate of dashpot to thereby ei'ect relativeiy delay in the operation of said trip ond armature operable when s'f 'roresponsive moans is energized in r Y overload currents above said predeternnneov Yalue to operate said valve to the iuil open position te admit cue '15 iluid-to said dashpot ata rateto permit instantaneous operation of said trip means, andseparate adjusting means Jfor said first and second armatures for selectively determining the minimum overload currents required to actuate said armatures.

13. In a circuit breaker having relatively movable contact means and operating means therefor, the combination or trip means, electroresponsive means for operating said trip means, time-delay means comprising a fluid dashpot or retarding tripping operation of said trip means, a valve operable to an intermediate position and to a full open position to admit to said dashpot, av first armature operable when said eleotroresponsive means is energized in response to overload en rents beloiv a predetermined value to operate said valve to said intermediate position to admit fluid to said dashpot at a rate to effect a time delay in the operation oi said trip means, and a second armature operable When saidelectroresponsive means is energized in respenseY to overload currents abovev said predetermined value to operate said valve to full open position to admit fluid to said dasnpot at a rate to' permit instantaneous operation of said trip means.

14. In a circuit breaker having relatively movable contact means and operating means therefor, the combination of trip means, electroresponsive means for operating said trip means, time-delay means comprising a iluid dashpot for retarding tripping operation of said trip means, a valve operable to an intermediate position and to a full open position to admit uid to said dashpot, a' first armature operable When said electroresponsive means is energized in response to overload currents below a predetermined value to operate said valve to said intermediate position to admit fluid to said daslipot at a rate to effect a time delay inthe operation of said trip means, and a second armature operable when said eleotroresponsivc means is energized in response to overload currents above said predetermined value to operate said valve t full open position to admit duid to said dashpot at a rate to permit instantaneous operation of said trip means, separa-te biasing means biasing said armatures against opera-tion, and separate adjusting means for varying the bias of said biasing means to vary the minimum overload currents required to operate said armatures.

15. In a circuit breaker having relatively'movable .contact means and operating means therefor, tbe combination of trip means, electroresponsive means for operating said trip means, time-delay means comprising a fluid dashpot for retarding tripping operation of said trip means, a valve operable to an intermediate position and to a full open position to admit iiuid to said dashpot, a pivot armature operable when said electroresponsive means is energized in response to overload currents below a predetermined value to operate said valve to said intermediate position to admit fluid to said dashpot at a rate to effect a time delay in the operation of said trip means, adjustable means for selectively determining the extent of opening of said valve by said first armature to vary the amount of time delay, and a second armature operable when said electroresponsive means is energized in response to overload currents above said predetermined value to operate said valve to full open position to admit fluid to said dashpot at 9.- rate to per-v mit instantaneous operation of said tripk means.

16. In an electromagnetic trip, device com'- prising a: trip, rod, a main armature movable to actuate said trip rod, time-delay means fork retarding tripping movement of said trip rod comprising a iluid dashpot connected to said trip rod, a single valve openable to admit fluid to said dashpot at diierent rates, and a plurality of valve-operating armatures operable upon energizationv of said electromagnetic means in response to overload currents o different magnitudes to open said valve diierent extents.

1'?. In an electromagnetic trip device comprising a trip rod, a main armature movable to actuate said trip rod, time-delay means for retarding tripping movementof said trip rod comprising a fluid dashpot connected to said trip rod, a single valve openable to admit fluid to said dashpot at diierent rates, and a plurality of valve-operating armatures operable upon energization of said electromagnetic means in respense to overload currents or different magnitudes to open4 said valve diierent extents, and adjustable means for varying the extent of opening movement or one of said armatures.

18. In an electromagnetic trip device comprising a trip rod, a main armature movable to actuate said trip rod, time-delay means for retarding tripping movement of said trip rod comprising a fluid dashpot connected to said trip rod, a single valve openable to admit fluid to said dashpot at different rates, and a plurality of valve-operating armatures operable upon energize-tion of said electromagnetic means in response to `overload currents or different magnitudes to open said valve diierent extents, separate biasing means for said main armature and each oi said valve operating armaturesy and a separate adjusting device for adjusting each of said biasing means to vary the minimum overload current required to operate said main armature and eaclrof said valve-operating armatures.

19. In a circuit breaker having relatively movable contact means and operating means therefor, the combination of a trip member, electromagnetic means for operating said trip member, a time-delay device for retarding operation of said trip member, a single control element for said time-delay device, said control element having a irst position in which said control element controls said time-delay device to eil-ect a relativelyr long time delay in the operation of said trip member, adjusting means for adjusting the first'position of said control element to vary the amount of time delay provide by said timedelay device in the iirst position of said control element, biasing means for said electromagnetic means, adjusting means for adjusting said biasing means to vary the minimum overload current required to operate said trip member, a first electroresponsi've means responsive to overload currents below a predetermined value to move said control element to a second position to effect a relatively short time delay in the operation of said trip member, adjusting means for adjusting said. second position of said control element to vary the amount oi time delay rovided by said time-delay device when said control element is in said second position, biasing means biasing said first electroresponsive means against operation, adjusting means for adjusting said biasing means to vary the minimum overload current required to operate said first electroresponsive means to move said control element to said second position, a second electroresponsive means responsive 17 to overload currents above said predetermined value to move said control element to a third position to effect instantaneous operation of said trip member, biasing means biasing said second electroresponsive means against operation, and adjusting. means for adjusting said biasing means to vary the minimum overload current required to operate said second eiectroresponsive means and move said :control element to said third position.

JOHN B. MACNEILL. HARRY J. LINGAL.

References cited in the me of this patent Number UNITED STATES PATENTS Name Date Wilhelm May 16, 1939 Lindstrom et a1. Oct. 19, 1948 Graves Nov. 1, 1949 Jensen Feb. 27, 1951

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