US2619568A - Circuit interrupter - Google Patents

Description

Nov. 25,-1952 w. M. LEEDS 2,619,568

CIRCUIT INTERRUPTER Filed April 4, 1947 3 Sheets-Sheet l WITNESSES: INVENTOR W01 f/IFOp YZ. e2 d5.

7%AZM W E /W Nov. 25, 1952 w. M. LEEDS 2,619,568

CIRCUIT INTERRUPTER Filed April 4, 1947 3 Sheets-Sheet 2 24 13' Z3 Z2 7 39 Z6 11 6 1; W

F z2 231 41 '1 m 23a is g; 41 66a I f 1 Z WITNESSES: I INVENTOR .,M BY w w Nov. 25, 1952 w. M. LEEDS CIRCUIT INTERRUPTER 3 Sheets-Sheet 5 Filed April 4, 1947 INVENTOR wmz/m mz eeds.

Q QATORNEY WITNESSES: 1;

Patented Nov. 25, 1952 CIRCUIT INTERRUPTER Winthrop M. Leeds, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 4, 1947, Serial No. 739,273

21 Claims.

This invention relates to circuit interrupters in general, and more particularly to are extinguishing structures and operating mechanisms therefor.

A general object of my invention is to provide one or more improved arc extinguishing assemblages including a plurality of improved arc extinguishing units or circuit interrupting elements in which an improved hydraulic operating mechanism is provided to effect operation of the contact structure.

Another object is to provide an improved circuit interrupter of the type comprising a pair of serially-related arc extinguishing assemblages which are electrically connected in the closed circuit position of the interrupter by a conducting cross-bar, and to provide an improved liquid pressure operating means for each assemblage to be actuated by the cross-bar.

Still another object is to provide an improved circuit interrupter in which longitudinal space is saved by providing one or more serially-related circuit interrupting elements in which the movable contact members are horizontally actuated.

A further object of my invention is to provide an improved are extinguishing assemblage including a plurality of circuit interrupting elements in which hydraulic means is employed to not only effect opening motion of the several movable contact members but also to provide fluid flow to effect extinction of the arcs.

Still another object is to provide an improved arc extinguishing assemblage comprising circuit interrupting elements of different types in which a hydraulic drive is employed to effect fluid motion into a circuit interrupting element of the pressure-generating type during low or intermediate values of current interruption, and in which the hydraulic drive will be ineffective to force fluid into the pressure-generating circuit interrupting element during the interruption of high power. Preferably, the pressure-generating circuit interrupting element is self-suflicient during the interruption of high power to force fluid flow into one or more circuit interrupting elements of the interrupting type.

Another object is to provide an improved arc extinguishing assemblage comprising two pairs of circuit interrupting elements of the pressuregenerating type and the interrupting type serially related and adapted for simultaneous operation in which the movable contact members are so adapted as to be horizontally actuated to save longitudinal space.

A further object is to provide an interrupter of the type specified in the preceding paragraph in which improved liquid pressure operating means are disposed at the lower end of the assemblage to be actuated by a movable bridging member.

Further objects and advantages will readily become apparent upon a reading of the following specification taken in conjunction with the drawings, in which:

Figure 1 is a side elevational view, partially in section, of a complete circuit interrupter embodying my invention and shown in the closed circuit position;

Fig. 2 is an enlarged side elevational view, partially in vertical section, of the left-hand are extinguishing assemblage of Fig. 1, the contact structure being shown in the partially open circuit position and the interruption of relatively low current being assumed;

Fig. 3 is a sectional view taken along the line IIIIII of Fig. 2;

Fig. 4 is a sectional view taken along the line IV--IV of Fig. 2;

Fig. 5 is an enlarged sectional view taken along the line V-V of Fig. 4;

Fig. 6 is a vertical sectional view through a modified form of my invention, the contact structure being shown in the closed circuit position; and

Fig. 7 is a sectional view VII-VII of Fig. 6. 7

Referring to the drawings, and more particularly to Fig. 1 thereof, the reference numeral I designates a tank filled to the level 2 with a suitable arc extinguishing fluid 3, in this instance circuit breaker oil. Depending from the cover 4 of the tank I are two terminal bushings 5 supporting at their lower ends identical arc extinguishing assemblages, generally designated by the reference numeral 6. The two are exuishing assemblages 6 are electrically interconnected in the closed circuit position of the interrupter, as shown in Fig. 1, by a conducting cross-bar i reciprocally operated in a vertical direction by an insulating lift rod 8.

The insulating lift rod 8 is actuated by suitable mechanism not disclosed but which is responsive to either manual operation or to the existence of excessive current conditions in the circuit controlled by the interrupter.

Referring more particularly to Fig. 2, which shows more clearly than does Fig. 1 the improved arc extinguishing assemblage of my invention, it will be observed that I have provided two pairs of circuit interrupting elements of two taken along the line difierent types. The first type of circuit inter-. rupting element is designated a pressure-generating circuit interrupting element and is generally designated by the reference numeral 9 in Fig. 2. The second type of circuit interrupting element is herein designated as an interrupting circuit interrupting element and is designated generally by the reference numeral ID in Fig. 2. Preferably; the four circuit interrupting elements 9, l are alternately disposed and threadedly supported in a substantially horizontal manner as shown in Fig. 2.

More specifically, the arc extinguishing assemblage 6 comprises an insulating cylindrital casing ll having its lower end closed by; a closure cap 12 formed of metal and threadedly' secured to. the casing II. The upper endoi the casin v II is likewise closed by an upper closure cap I3 threadedly secured to the upper end of the casing ll. The contact foot Id of the assemblage 6 is secured by bolts to the cap I 3.

The pressure-generating circuit interrupting elements 9 are identical. in construction; consequently, only a description of one is necessary. Referring to Fig. 2, it will be apparent that the pressure-generating circuit interrupting element or pressure genera-ting arc extinguishing unit 3 includes stationary contact means, generally designated by the reference numeral I5, and including a. stationary contact il cooperable with a rod-shaped movable contact member I 8 to establish a. press-ureegenerating are designated. by the reference numeral 19 in Fig. 2.

For causing the actuation of the movable contact member I 8, I'providea liquid. pressure actuated operating means, generally designated by the reference numeral 25. The. operating means 20, preferably consist of an. operating piston 21 rigidly secured to the movable contact member l8- intermediate the ends thereof and biased toward the right, as viewed in Fig. 2,.by a compression closing spring 22. The compression spring 22 seats at its right-hand end against the operating piston. 2| and seats at its left-hand end against a metallic ring-shaped plate 23 secured by any suitablev means such as screws. 23a to the cylindrical extension. 23b of the insulating tubular casing 24 of the circuit interrupting element 9..

It will be observed that the stationary contact means 16. is part. of a removable tubular conducti ing member 25 secured to the interrupting element 9. by screws 25a which terminate in a cylindricalextension 2.5. of the tubular casing 24. The removable contact member 25 is. laterally removable. from the. assemblage 5 upon the, removal of the screws 251;.

Also, the contact member 25 has a passage 2,? formed therein to permit communication between the pressure-generating, circuit, interrupting element 9 and the interrupting circuit interrupting element H1 disposedat the upper extremity of the assemblage 6... The arrows 28 indicate such a passage offluid, in this instance oil, under pres sure from the unit 9 to the unit it to efiect the extinction of the interrupting are 29. drawn in the latter.

Referring to Fig. 2, taken in coniunction with Fig. 4, it will be observed that the movable contact member i8- enters. a. multi-orifice structure formed by the use of a plurality of suitably configured insulating plates disposed in contiguous relation and held in position by the insulating tie bolts 6 As more clearly shown in Fig. 5, the plates are of three different types. The. first type herein designated n n l t n n e plate and is generally designated by the reference numeral 39, being shown more clearly in Fig. 5. The inlet plate 39 comprises two insulating halves 3| disposed on the same level and separated to form a pair of inwardly extendin inlet passages 32 leading from the casing II to the interior of the pressure-generating circuit interrupting element 9. Preferably, I provide valve means generally designated by the reference numeral 33 controlling the passage of fluid through the inlet passages 32.

More specifically, the valve means 33 includes a pair of gate valves 34 pivotally mounted at 35 and biased toward the closed position as shown by the. dotted lines 36 of Fig. 5 by a coil spring 3? encircliing the pivot pin 35. It will be observed that the passage of oil into the unit 9 during'the interruption of low and medium powers will cause opening of the valve means 33 as shown in Fig. 5. During the interruption of high powers when the pressure generated at the pressuregenerating are 19 is sumcient to cause the requisite fiuid flow toward the interrupting circuit interrupting element Hi, the pressure within the unit 9 will overcome the pressure of the oil entering, into the unit 9 and cause closure of the valve means 33, the purpose for which will appear more fully hereinafter.

The insulatin inlet plate 30 hascut-outportions 38 provided in each. insulating half 31, the purpose for which will also appear more clearly hereinafter.

I have provided three. of the insulating inlet plates 30 grouped. together as shown more clearly in Fig. 2. Adjacent the end inlet plates are insulating orifice plates designated by the reference numeral 39, and having a confi uration more clearly shown in Fig. 2 and Fig. 5. Each orifice plate 39 has formed therein the cut-out portions 38 and also a, centrally disposed orifice designated by the reference numeral 36, through which the movable contact member it passes during its opening movement. Adjacent each orifice. plate;39 is an insulating exhaust plate designated by the reference numeral ii, and having a configuration more clearly shown in Fig. 5.

The exhaust plate. M has an enlarged cut-out portion 42 provided therein, the configuration of which is more clearly shown in Fig. 5.

The cut-out portions 38 of the inlet plates 39 and the orifice plates 39 align to form horizontally extending passages, generally designated. by the reference numeral $3, and permitting fluid communication from the pressure are l9 to the passage. 2.! provided in the removable contact member 25.

The interrupting, arc extinguishing unit It] will now be described. The interrupting unit H] is also provided With a movable contact member [8, an operating piston 21, a closing spring 22, ring.- shaped closure plate 23 and stationary contact means [5 identical in configuration to that employed in the pressure unit 9. Thus, the'contact construction for the uni-t It} is. exactly the same as the unit 9 and is hydraulically operated inv the same manner. The interrupting chamber 44 for the interrupting are 29 established within, the interrupting unit Hi is formed by the superpositioning of a plurality of insulating plates similar in shape to those previously described in connection with the unit 9 and hence given the same reference numerals.

More specifically, I have provided orifice in:- sulating plates 35 which are the same as. those :ere iousu described Also. t p a s, 41 whi were termed exhaust plates in the unit 9 are also employed in the unit 10, but in the unit I6 may be termed inlet plates 4 l. Thus, the plates II in the unit 9' permitted the exhaust of fluid away from the pressure-generating arc IS]. The inlet plates 4| of the unit have exactly the same shape as the exhaust plates 4| of the unit 9, but in the unit It permit the flow of fluid, in this instance oil under pressure, from the horizontally extending passages 43 radially inwardly toward the interrupting are 29 to effect the extinction of the latter.

The third type of plate employed in the interrupting unit It has the same configuration as the inlet insulating plate 30, previously described, and is in the unit it) designated by the same reference numeral. However, the insulating inlet plate 30 is in the unit In designated as an exhaust insulating plate so inasmuch as it permits the fluid flow to pass in the opposite direction to that permitted in the unit 9. Thus, the oil flows out of the unit l0 through the exhaust insulating plates 39. To allow the oil to exhaust out of the casing ll tubular members #5 of insulating material are provided which are threadedly secured into apertures 45a of the casing H. As a result, the tubular members 45 permit the exhaust of fluid out of the unit l8 through the exhaust plates and to the region entirely exterior of the casing II.

It will be observed that the pressure-generating chamber 46 is formed by a sub-assembly plate structure including the plates 38, 39, ll and the end plates 65, 66 held together as a unit by the tie bolts 64. The heads of the bolts 64 abut against the plate 66. The ends of the tie bolts 64 are threaded through apertures provided in the other end plate 555. The plates 65, 65 have annular grooves 65a, 6611 provided therein, as shown in Fig. 2, to permit the sub-assembly plate structure to be held rigidly in place by compressive forces exerted by the tubular cylinders 23b, 26 forming the ends of the tubular casing 24.

The interrupting chamber 44 is likewise formed as a sub-assembly plate structure held together as a sub-unit by the insulating tie bolts 55. The end plates 55, 66 of the sub-assembly are also grooved at 65a, 66a to permit the compression members 23b and 2G to hold the sub-assembly rigidly in place.

The sides of each interrupting chamber subassembly are counterbored as at 651) in Fig. 3 to permit the flat ended tubes t5 to come to a flush stop against the flat counterbored sides B511 of the plate sub-assembly, as shown in Fig. 3.

Certain features of the pressure-generating chamber 45 of the pressure-generating unit 9 and the interrupting chamber 44 of the interrupting unit IQ are set forth and claimed in U. S. patent application, Serial No. 552,132, filed August 31, 194%, now U. Patent 2,445,442, issued July 20, 1948, to Winthrop M. Leeds and Robert E. Friedrich and assigned to the assignee of the instant application.

I have provided an improved hydraulic drive or hydraulic operating mechanism, generally designated by the reference numeral 41, and including a liquid moving device 48 disposed adjacent the lower end of the assemblage 6. Preferably, the liquid moving device 48 includes a pump piston 49 operating within a metallic actuating cylinder 59 and biased downwardly in the circuit opening direction by a battery of compression springs 51. The pump piston 49 has a downwardly extending projection 52 integrally 6 formed therewith which is engaged in abutting relationship by the extremity 53 of the conducting cross-bar I, as shown more clearly in Fig. 2.

The cylinder is secured as by welding to the closure cap 12 of the casing H. A venting passage 53a is provided through the projection 52 so that oil may easily circulate to the back side of the piston 49.

Thus, during the closing operation, the upward movement of the cross-bar l as caused by upward closing movement of the lift rod 8, eifects upward charging closing movement of the pump piston 49 against the downward biasing action exerted by the battery of compression springs 5|.

During the opening operation, suitable mechanism, not shown, but which is responsive to either manual operation or to the existence of overloads existing in the circuit controlled by the interrupter causes downward opening movement of the lift rod 8. The downward movement of the lift rod 8 causes corresponding downward opening movement of the conducting cross-bar 1. The downward motion of the bridging memher 1' permits the compression springs 5| to force or drive the pump piston 49 downwardly to thereby eifect the flow of oil under pressure out of the pump chamber 54 and outwardly through apertures 55 provided at the lower end of the operating cylinder 58 and upwardly through an annular passage 5t as provided between the walls of the casing II and the cylinder 56. The operating oil under pressure, passing upwardly through the annular passage 56, enters the inlet passages 32 provided by the inlet plates 30 of the two pressure-generating arc extinguishing units 5 of the assemblage 6. The operating liquid also passes through apertures 63 in the several tubes 2% of the units 9, ill to act upon the several pistons 2i to thereby effect simultaneous opening of the several movable contacts l3.

This is assuming a state of aifairs where low or medium powers are being interrupted. The oil under pressure as caused by downward movement of the pump piston 49 is sufiicient to cause opening of the valve means 33, as indicated by the full lines in Fig. 5, to permit the passage of oil under pressure through the inlet passages 32 to strike the pressure-generating are (9 drawn by the cooperation of the contacts l1, 18.

After striking the pressure-generating arc IS, the oil passes through the orifices 40 provided by the insulating orifice plates 38 to pass outwardly within the cut-out portion 42 as provided by the insulating exhaust plates 4! of the units 9. The oil under pressure then passes along the horizontally disposed passages 43 to enter the conduits 2! as provided by the two removable contact members 25 of the assemblage 6. After passing through the two contact members 25 the oil enters into the two interrupting are extinguishing units it) to pass along the horizontally disposed passages 43.

Then the oil passes radially inwardly as provided by the cut-out portions 42 of the inlet plates 4! of the units Hi to strike the interrupting are 29 drawn between the interrupting contacts ll, l8. After striking the interrupting are 29, the oil under pressure flows longitudinaliy of the are 29 through the orifices 40 provided by the orifice insulating plates 39 to pass completely out of the units l0 and also out of the casing ll through exhaust passages 32 as provided by the insulating exhaust plates 30 of th units [0. 7

Thus, during the interruption of low or meenacts 111111 values of Ql Irent, the hydraulic drive 47 is; operable not only'to force simultaneous opening motion of the several movable contact members l8, .but isalso operable to effect fluid motion into the two pressure-generating units 9 as permitted by opening of the valve means 33.

During the interruption of high powers, on the other hand, the pressure generated at the pressure-generating arcs [9- will overcome the pressure of the oil as caused by operation of the liquid moving device 43 to thereby cause closure of the valve means 33. This will prevent gas and contaminated oil from the pressure units 9 from passing out of the said units. through the inlet passages 32; in a reverse direction from that: during normal. Qperation so as to enter the casing i. I. If this were permitted to happen, the gas and. contaminated oil entering the casing H. during the interruption of high short-circuit currents, would reduce the dielectric strength of the-medium between successive interrupting units 9- and H]. Also the cushioning effect of gas bubbles inside the casing I! would reduce the effectiveness of the liquid moving device d3 when several operations are attempted in rapid succession.

Consequently, the provision of the valve means 33' in the inlet passages 32 of the pressure units 9 prevents contaminated gas and oil from entering the casing H during the interruption of high short-circuit currents when the pressure generated at the pressure-generating arcs I9 is of itself suflicient to cause the requisite fluid flow under pressure through. the contact members toward the interrupting units It.

It is obvious from the foregoing description that the circuit through the interrupter in the closed circuit position thereof includes the terminal, stud, not shown, passing through the terminal bushing 5, contact foot Hi, flexible conductor 5.! to movable interrupting contact it of the upper interrupting. unit H] of the assemblage 6. The circuit then passes through the upper removable contact member 25v to the upper pressure-generating unit 9, from whence the circuit passes through the movable pressure-generating contact l8 associated with the upper pressuregenerating unit 9, through the flexible conductor 58 to the movable interrupting contact it! of the lower interrupting unit It.

The circuit then extends through the lower contact member 2-5 into the lower pressure-gencrating unit 9. The electrical circuit then extends through the movable pressure-generating contact iii of the lower pressure unit 9 through a fleX-ible conductor 59 to the conducting lower closure cap l2 of the assemblage 6.

I have provided a pair of stationary disconnect fingers which make electrical contact with the sides of the cross-bar 7 during the initial portion of the opening operation so that the arcs are interrupted within the several units 9-; l0, before the cross-bar 7 parts company with the stationary disconnect fingers 69. Thus, the circuit is broken within the units Q, Hi and not at the disconnect fingers 50.

The cross-bar 7 moves downwardly during the opening operation to assume a position as shown by the dotted lines 6| of Fig. 1 in which position two isolating gaps are interposed in the circuit.

High speed oil circuit breakers for 230' kv. ratings and above usually utilize multi-break con tact arrangements. The mechanical linkages for operating these Contacts simultaneously may become complicated. My invention, as dis:

closed above, provides hydraulic operation of multi-break contacts making use of the sameipis-fl ton required for developing pressuretointerrupt line charging currents or other low or medium currents.

Bythis arrangement thecontacts are. made. to open horizontally giving easy accessibility for inspection. During the opening stroke, heavy springs 51 behind the main piston 49, located at the bottom of the assemblage 6 put all of the oil in the large supporting tube II under pressure. Thus, each of the four moving contacts I8 is opened rapidly, by hydraulic pressure ap... plied to the contact. pistons 21 During the interruption of low or medium cur-. rents, oil is forced through the, inlet channels 32 of the second and fourth grids, or pressure: generating grids 9, through the multi-orifice structure to conduits 23 leading. to the hollow stationary contacts ii. The oil then flows up wardly to the first and third. interrupting grids iii. After passing through another multi-orifice structure associated with the interrupting grids it, where. the interrupting arcs 29 are deionized, oil and gas are discharged through the front and back vent openings 62 provided by the tubular members 55 as shown, in Fig. 3.

During the interruption of heavy short-circuit currents, the deionizing flow into the, first and third grids It is put in motionby the pressure generated in the second and fourth grids 9, or pressure breaks.

The provision of the check valves 33 located in the inlet passages 32 of the second and fourth pressure grids 9 avoids gas being expelled into the main tube i i. The main piston 9 will, operate even during high current. interruption to force the contact pistons 2! to open hydraulically. After arc extinction, valves 33 open and completion of the main piston stroke will send a flushing flow or" oil through all of the grids 9, it.

The springs 22 will then retrieve the contacts it, ill to permit closing of the circuit to take place at the disconnect fingers 5&3, thereby avoiding prestriking between the contacts during the closing stroke. When closing again t a fault, gas and contaminated oil from even a short closing arc may reduce the interrupting effectiveness on the opening operation immediately following. From the foregoing description, it will be apparent that I have provided an improved arc extinguishing assemblage in which the circuit is interrupted within the units 9, IE3, and during the closing stroke the contact structure already being closed by the springs 22 in. the assemblage i5 completion of the circuit oc curs exteriorly of the casing ii at the disconnect fingers 85. Thus, contamination of the oil due to prestriking on the closing stroke will occur exteriorly of the casing ii and not interiorly of the units 9, it. The term prestriking is meant herein to mean arcing between the approaching contacts during the closing operation when voltage is impressed upon the system. In a high voltage system, the high voltage encountered tends to. cause flashover between the approaching contacts even before the contacts have actually made contacting engagement during such a closing operation. Certain features of closing the contact structure within the as semblage 6 in the full. open circuit position of the interrupter, so that the circuit will be made exteriorly thereof during the, closing. stroke are 9 described and claimed in my copending application, Serial No. 679,087 filed June 25, 1946, continued as application, Serial No. 103,683, filed July 8, 1949 which issued as Patent No. 2,580,354 on December 25, 1951, and assigned to the assignee of the instant application.

In the modification of my invention, as shown in Figs. 6 and 7, it will be noted that I have provided a modified type of hydraulic drive 61 which includes a pump piston 68 disposed adjacent the upper end of the arc extinguishing unit 69. The pump piston 58 is reciprocally operable within an operating cylinder 10 provided integrally with a modified contact foot H, the latter being threadedly secured at 12 to the lower end of a con-ducting tube 13 extending interiorly through the terminal bushing 5.

I have provided a relatively stationary contact 14 disposed intermediate the ends of the unit 60 and making engagement in the closed circuit position of the interrupter, as shown in Fig. 6, with an upper pressure-geenerating contact I and a lower interrupting contact 16.

Downward movement of the pump piston 68 as caused by the compression springs 11 effects the motion of fluid, in this instance oil, under pressure downwardly and against the operating pistons 18, secured respectively to the pressure and interrupting contacts I5, 16. The oil under pressure forces the opening movement of the contacts 15, 16 against the closing biasing action exerted by compression springs 80, 8I. The movement of the contact upwardly away from the intermediate contact 14 draws a pressuregenerating are, not shown, within a pressuregenerating chamber 82. The downward motion of the lower movable interrupting contact 15 draws an interrupting arc, not shown, within an interrupting chamber, generally designated by the reference numeral 03 in Fig. 6. The pump piston 53 has an insulating projection 84 extending downwardly therefrom which makes abutting engagement with an oifsta-nding insulating arm or actuating part 85 rigidly secured at 83 to the insulating lift rod 8 of the interrupter. As in the preceding embodiment o'f my invention, the conducting cross-bar 1 makes contacting engagement in the closed circuit position of the interrupter, as shown in Fig. 5, with a pair of stationary disconnect fingers 60, only one of which is shown in Fig. 6.

It will be observed from an inspection of Fig. 6 that oil under pressure passes downwardly through a conduit 81 to pass inwardly through two inlet passages 38 toward the pressure-gencrating arc established between the contacts I4, 15. After striking the pressure-generating arc, the oil flows longitudinally through orifices 89 provided by orifice insulating plates 90, 0| and 02 to discharge through exhaust passages E53 provided by insulating exhaust plates '84, S5. The plates are provided with cut-out portions 95 which upon alignment form a vertical fiow passage, generally designated by the reference numeral 01 and leading downwardly toward the interrupting chamber 83.

The oil passing downwardly through the vertical flow passage 91 under pressure as provided by the pressure-generating arc and/ or the pump piston 68 enters the interrupting chamber 83 through inlet passages 99 provided by insulating plates 99a, 9%. After striking the interrupting arc drawn between the contacts I4, 16 within the interrupting chamber 83 the oil passes longitudinally of the said interrupting are through 10' orifices I00 provided by insulating orifice plates IOI to pass outwardly out of the unit 69 through exhaust passages I02 as more clearly shown in Fig. 7.

The exhaust passages I02 are provided by an insulating exhaust plate, generally designated by the reference numeral I03, and including two separated insulating halves I04, I05. The insulating half I04 has the cut-out portion 95 provided therein and the insulating half I05 has a segment I06 removed therefrom to permit downward travel of the insulating arm 85. Also, the insulating half I05 has an aperture I01 formed therein which upon alignment with apertures I01 formed in the other adjoining plates forms a vertical conduit, generally designated by the reference number I08, permitting intercommunication between the pump piston 68 and the operating piston 19 secured to the lower end of the movable interrupting contact 16. Sliding fingers H0, III are respectively secured to the operating pistons 18, 19 to provide sliding contacting engagement along the end portions H2, H3 of the operating cylinders H4, H5 respectively.

Thus, in the closed circuit position of the interrupter, as shown in Fig. 6, the electrical circuit therethrough includes conducting tube 13 positioned interiorly of the terminal bushing 5, contact foot 1|, portion II2 of casting H, fingers I I0, movable pressure-generating contacts 15, intermediate stationary contact 14, lower movable interrupting contact 16, fingers III, portion H3 of operating cylinder H5 to the stationary disconnect fingers 60. The circuit then extends through the conducting cross-bar I to the righthand are extinguishing unit 69, not shown, of the complete interrupter. The circuit extends through the right-hand unit 69 in an identical manner to its passage through the left-hand unit 69 shown in Fig. 6 to the right hand terminal bushing 5 of the interrupter.

During the interruption of relatively low or intermediate values of current, the pump piston 68 moves downwardly to force oil to fiow through the conduit 81 and the conduit I08 toward the operating pistons 18, 19 respectively. This causes upward and downward motion respectively of contacts 15, 16 to effect thereby simultaneous drawing of a pressure-generating are, not shown, within the pressure-generating chamber 82 and an interrupting are, not shown, within the interrupting chamber 83. Fluid, in this instance o1l, passes in a manner as previously mentioned toward the pressure are and downwardly through the passage 91 to the interrupting arc to eifect the extinction of the latter. Circuit interruption soon follows and the continued downward motion of the cross-bar I effects separation from the disconnect fingers to interpose an isolating gap in the circuit.

During the interruption of high power, that is, during the interruption of large amperage currents, the pressure established within the pressure-generating chamber 82 stalls the downward movement of the pump piston 68. However, the pressure established at the pressure-generating chamber 82 causes oil to flow downwardly through the conduit I08 to eiTect opening movement of the sliding piston 19 even more rapidly than usual. Also, some of the oil under pressure at the pressure-generating chamber 82 passes upwardly to flow through the conduit 81 to act upwardly upon the operating piston 18 to eifect opening motion of the movable pressuregenerating contact 15.

Further, oil under pressure passes downwardly from the pressure chamber 82 through the vertical flow passage 9! to pass into the interrupting chamber 83 to efiect interruption of the interrupting arc in the manner previously mentioned.

Upon a subsidenceof the pressure within the unit 69, downward motion of the pump piston 68 following the interruption of such high power causes a flushing flow of oil to take place through the pressure chamber-82 and through the'interrupting chamber 83.

During the closing stroke, it will be noted that electrical contact is not made between the conducting cross-bar 1 and the disconnect fingers 6U until after the main piston 68 has been lifted part way. This has theadvantage that should the-breaker be closed during the existence of short-circuitconditions still existing in the line controlled by the interrupter, the immediate 'reversal of the operating-mechanism as caused by such closing on a short-circuit will permit the piston 68 to beefiective to cause opening of the contacts in the manner previously described. Thus I have provided anarrangement in which the piston 68 is part way charged before there is any possibility of flashover between the disconnect contact 60 and the cross-bar '1 when closing on a short circuit.

It will be observed that the construction as set forth in Figs. 6 and 7 is particularly suitable where the voltage encountered is not as high as that which requires a greater number of breaks. Thus, where a greater number of breaks is necessary, the construction of Fig. 2 may be employed. For lower voltage applications the construction of Fig. 6 may be adequate.

From the foregoing description of two embodi ments of my invention, it will be'apparent that I have provided an improved circuit interrupter of the type utilizing a hydraulic drive for efiecting opening of the contact structure and for also directing fluid or liquid under pressure into the interrupting chambers during the interruption of low or medium powers to eiiect the extinction of the arcs drawn therein. During the interruption of high powers, the pressure generated at the pressure are is suflicient to provide the requisite fluid flow and the main pump pistons may be stalled, to later bring about a flushing 'fiow of fluid following circuit interruption.

It will be noted that with the construction of Fig. 2, the contact structure is removable laterally from the assemblage for inspection'or replacement. Also, with the construction of Fig. 2, the number of pairs of units may be accommodated to the voltage rating. Thus, two of the units, instead of four as shown in Fig. 2, may be used for moderate voltage applications. For very high voltages, six or even eight units may be provided.

It will also be observed that with the construction shown, the contact structure is reclosed by spring pressure in the fully open circuit position of the interrupter so that closing of the circuit takes place exteriorly of the assemblage S or the unit 69. Thus, prestriking or flashover during the closing stroke will not tend to contaminate oi1 within the assemblage 5 or the unit 69.

Although I have shown and described specific structures, it is to be clearly understood that the same were merely for the purpose or" illustration, and that changes and modifications may readily be made therein by those skilled in the art without departing from the spirit and scope of the appended claims.

'I'claim-as my invention 1. In a circuit interrupter of the liquidbreak type, an arc extinguishing assemblage including hollow casing means, a pressure-generating circuit interrupting element having a pair or separable contacts provided therein, the pressuregenerating element being supported substantially transversely of the casing means, aninterrupting circuit interrupting element also having a pair of separable contacts provided therein, the interrupting circuit interrupting element being supported substantially transversely of the casing means, liquid passage means interconnecting the interior or" the hollow casing means with the pressure-generating element, passage means disposed externally of the casing means interconnecting the two circuit interrupting elements so that liquid under pressure from the pressuregenerating circuit interrupting elementmay flow therethrough to extinguish arcing within the interruptii'ig circuit interrupting element, and exhaust passage means for the interrupting element extending completely out of the casing means.

2. In a circuit interrupter of the liquid break type, an arc extinguishing assemblage including hollow casing means filled with liquid, a pressuregenerating circuit interrupting element having a pair of separable contacts provided therein, the pressure-generating element being supported substantially transversely by the hollow casing means, an interrupting circuit interrupting element also having a pair of separable contacts provided therein, the interrupting circuit interrupting element being supported substantially transversely by the hollow casing means, liquid passage means interconnecting the interior ofthe casing means with the pressure-generating element, passage means disposed externally of the casing means interconnecting the two circuit interrupting elements, exhaust passage means for the interrupting element extending completely out of the casing means, and valve means dis posed in the first-mentioned passage means to prevent back flow of gas or liquid from the pressure-generating element into the casing means during high current interruption.

3. In a circuit interrupter of the liquid break type, an arc extinguishing assemblage including hollow casing means filled with liquid, a pressure-generating circuit interrupting element having a pair of separable contacts provided therein, the pressure-generating element being supported substantially transversely of the casing means, an interrupting circuit interrupting element also having a pair of separable contacts provided therein, the interrupting circuit interrupting element being supported substantially transversely of the casing means, liquid passage means interconnecting the interior of the casing means with the pressure-generating element, passage means disposed externally of the casing means interconnecting the two circuit interrupting elements, exhaust passage means for the interrupting element, extending completely out of the casing means, and a hydraulic operating mechanism disposed at one end of the casing means for efiecting simultaneous separation of the two pairs of separable contacts within the two circuit interrupting elements.

4. In a circuit interrupter, contact means for establishing a pressure-generating are within a substantially confined pressure-generating chamber, contact means for establishing an interrupt ing are within a vented interrupting chamber,

13 passage means interconnecting the two chambers so that fluid from the pressure chamber may flow toward the interrupting chamber to effect the extinction of the arc therein, biasing means for biasing both contact means to the closed circuit position, disconnect means, hydraulic operating means for efiecting simultaneous opening of the contact means against the biasing action exerted by the biasing means, means whereby the disconnect means causes operation of the hydraulic operating means, and passage means interconnecting the hydraulic operating means with the pressure-generating chamber to assist low current interruption so that liquid may flow sequentially toward the pressure-generating arc and subsequently onwardly through said first-mentioned passage means to the interrupting are.

5. In a circuit interrupter of the liquid break type, a tubular insulating casing filled with liquid, two pairs of pressure-generating and interrupting circuit interrupting elements disposed alternately and supported substantially transversely by the tubular casing, passage means disposed externally of the casing connecting the two pairs of elements so that liquid under pressure from the pressure-generating elements may extinguish arcing within the interrupting circuit interrupting elements, and contact means for all the elements removable laterally from the casing.

6. In a circuit interrupter, a hollow casing, a pair of circuit interrupting elements supported transversely by the casing, one being a pressuregenerating element and the other being an interrupting element, contact rod means removable laterally from one end of each element, and a tubular stationary contact member interconnectin the two elements at their other ends for permitting the passage of fluid between the two elements.

7. In a circuit interrupter of the liquid break type, a tank containing an arc extinguishing liquid, means supporting a tubular casing adjacent one end thereof within the tank, a pair of tubular circuit interrupting elements supported by the casing substantially transversely thereto, disconnect means disposed at the other end of the casing, contact means for the elements laterally separable and laterally removable from the elements, hydraulic means for operating the contact means, and means whereby the disconnect means causes actuation of the hydraulic means.

8. In a circuit interrupter of the liquid break type, a tank containing an arc extinguishing liquid, means supporting a tubular casing adjacent one end thereof within the tank, a pair of tubular circuit interrupting elements supported by the casing substantially transversely thereto and extending therethrough, disconnect means disposed at the other end of the casing, contact means for the elements laterally separable and laterally removable from the elements, and a hydraulic drive disposed at the said other end of the casing actuated by the disconnect means and operable to effect simultaneous motion of the contact means in the two elements.

9. In a circuit interrupter of the liquid break type, contact means separable to establish substantially simultaneously a serially related pressure-generating arc and an interrupting arc, passage means interconnecting the two arcs so that liquid under pressure may flow from the pressure-generating arc toward the interrupting arc to effect the extinction of the latter, means biasin the contact means towards the closed circuit position, disconnect means, hydraulic operating means, means whereby the disconnect means causes charging motion of the hydraulic operating means during the closing stroke of the interrupter, and passage means interconnecting the hydraulic operating means with the two arcs so that liquid under pressure may fiow, at least during low current interruption, from the hydraulic operating means toward the pressure-generating arc and subsequently onwardly through said passage means toward the interrupting arc.

10. In a circuit interrupter of the liquid break type, an arc extinguishing assemblage including a hollow casing filled with liquid, a plurality of serially related arc extinguishing units supported substantially transversely of the casing, each unit having at least a movable contact member adapted for motion, a liquid pressure operating means associated with each unit for causing the motion of the movable contact member, means causing communication between the interior of the hollow casing and each liquid pressure operating means, a hydraulic drive for simultaneously effecting opening motion of the contact members by suddenly putting the liquid disposed within the hollow casing under pressure, and a conducting actuating member for charging the hydraulic drive during the closing operation of the circuit interrupter and separable from the hollow casing in the fully open circuit position of the interrupter for inserting an isolating gap in the circuit.

11. In a circuit interrupter of the liquid break type, an arc extinguishing assemblage including hollow casing means filled with liquid, a pressuregenerating circuit interrupting element having a pair of separable contacts provided therein, the pressure-generating element being supported substantially transversely of the casing means, an interrupting circuit interrupting element also having a pair of separable contacts provided therein, the interrupting circuit interruptin element being supported substantially transversely of the casing means, liquid passage means interconnecting the interior of the casing means with the pressure-generating element, separate passage means interconnecting the two circuit interrupting elements so that liquid under pressure from the pressure-generating circuit interruptin element may flow therethrough to extinguish arcing within the interrupting circuit interrupting element, exhaust passage means for the interrupting element extending completely out of the casing means, and a hydraulic operating mechanism for effecting simultaneous separation of the two pairs of separable contacts by putting the liquid within the casing under pressure.

12. In a. circuit interrupter of the liquid break type, an arc extinguishin assemblage including hollow casing means filled with liquid, a pressuregenerating circuit interrupting element having a pair of separable contacts provided therein, the pressure-generating element being supported substantially transversely of the casing means, an interrupting circuit interrupting element also having a pair of separable contacts provided therein, the interrupting circuit interrupting element being supported substantially transversely of the casing means, liquid passage means interconnecting the interior of the casing means with the pressure-generating element, passage means interconnecting the two circuit interrupting elements, exhaust passage means for the interrupting element extending completely out of the casing means, a hydraulic operating mechanism disposed adjacent one end of the casing means for e'fi ecting -"simultaneous separation of the :two pairs of separable contacts by putting the liquid within the casing under pressure, and a 'conducting actuating member for charging the hydraulic operating mechanism during the closing operation'of the interrupter and separable'away from the casing means in the fullyopen circuit position of the interrupter forplacing anisOlating-gap into the circuit.

13. In a 'circuit'interrupter of the liquid break type, an arc extinguishing assemblage includin hollow casing means, a pressure-generating circuitinterrupting-element having a pair of separable contacts provided therein, the pressuregenerating' element being supported bythe casing means, an'interrupting circuit interrupting element also having a pair of :separa'ble contacts provided therein, the interrupting circuit interruptingelement being supported by the casing means, liquid passage means interconnecting the interior of the hollow casing means with the pressure-generating element, passage means interconnecting the two circuit interrupting elements so that liquid under pressure from the pressure-generating circuit interrupting element may flow therethrough "to extinguish arcing within the interrupting circuitinterrupting element, and exhaust passage means for the interrupting element extending completely out of the casing means.

14. In a circuit interrupter of the liquid break type, an arc extinguishing assemblage including a hollow casingfilled with liquid, a plurality'of seriallyrelated arc extinguishing units supported substantially transversely by the casing, each unit having at least a movable'contact member adapted for motion, a liquid pressure operating means associated with each unit for causing the motion of the movable contact member, means causing communication between the interior of the hollow casing and each liquid pressure operating means, ahydraulic drive for simultaneously effectingopening-motion of the contact members by suddenly putting the liquid disposed within the casing under pressure, and a conductive tubular conduit interconnecting at least a pair of the arc extinguishing 'units for permitting the flow of liquid between the units and also for electrically connecting said pair'in series.

15. A circuit interrupter of the liquid break type including anarc extinguishing assemblage, the arc extinguishing assemblage comprising an arc extinguishing unit, means supporting the arc extinguishing assemblage adjacent one end thereof withinan arc extinguishing liquid, contact structure associated with the arc extinguishing unit to establish an arc, a liquid pressure operating means associated with the unit for causing separation of the contact structure associated therewith, a hydraulic drive including a piston for putting a liquid under pressure to efiect operation of the liquid pressure operating means, a relatively stationarydisconnect contact member disposed adjacent the'other end of the arc extinguishing assemblage, a movable disconnect contact member including an actuating part separable away from the relatively stationary disconnect contact and also away from the assemblage during the opening "operation of the interrupter for inserting an isolating gap in the circuit, and the actuating part causing part charging of the piston during the closing operation prior to closing of the electrical circuit through the interrupter.

16. A circuit interrupter of the liquid break type including a tank containing an arc extinguishing liquid, an arc extinguishing assemblage comprising anarc extinguishing unit, .means sup porting the arc extinguishing assemblage adjacent one end thereof within the liquid, contact structure associated with the arc extinguishing unit to establish arcing, means biasing the contact structure to the close .circuit position, ;a liquid pressure operating means associated with the unit for causing separation of 'the contact structure, a hydraulic drive including a piston for putting liquid under pressure to-efiect operation of the liquid pressure operating means :to thereby cause separation of the contact structure against the biasing action exerted by said biasing means, .a relatively stationary disconnect contact member'disposed adjacent-the other end of said are extinguishing assemblage, ;a movable disconnect contact member including an actuating part separable away from the "relatively stationary disconnect contact member and also away from the arc extinguishing assemblage during the opening operation for inserting an isolating gap in the circuit, the contact structure being closed in the fully opencircuitposition of the interrupter so that during theclosing operation the circuit is made at the "disconnect contacts, .and the actuating part causing part charging of the pistonduring the-'closing-operationrprior to closing of the electrical-circuit 'at the disconnect contacts.

17. In a circuit interrupter of the liquid "break type, .an arc extinguishing assemblage including hollow casing means, apressure-gieneratingzcircult interrupting element having a'pair of scparable contacts provided therein, the pressuregenerating element being supported substantially transversely of the casing means, an interrupting circuit interrupting element also having ajpair of separable contacts provided therein, the ,interrupting circuit interrupting element being supported substantially transversely of the casing means, liquid passage means interconnecting the interior of the hollow casing'means with the pressure-generating element, passage means interconnecting the two circuit interruptingelements so that liquid under pressure from the pressure-generating circuit interrupting element may flow therethrough to extinguish arcing within the interrupting circuit interrupting element, and exhaust passage means for the interrupting element extending completely out of the casing means.

18. In a circuit interrupter of the liquid break type, an arc extinguishing assemblage including hollow casing means filled with liquid, a pressure-generating circuit interrupting element having a pair of'separable contacts provided therein, the pressure-generating element being supported substantially transversely by the hollow casing means, an interrupting circuit interrupting element also having a pair of separable contacts provided therein, the interrupting circuit interrupting element being supported substantially transversely by the hollow casing meansliquid passage means interconnecting theinteriorof the casing means with thepressure-generating element, passage means interconnecting 'the two circuit interrupting elements, exhaust passage means for the interrupting element extending completely out of the casing means and yalve means disposed in the first-mentioned passage means to prevent back flow of gas orliquid from the. pressure-generating. element. into the casing means during high current interruption.

19. In a circuit interrupter, contact means for establishing a pressure-generating arc within a substantially confined pressure-generating chamber, contact means for establishing an interrupting are within a vented interrupting chamber, passage means interconnecting the two chambers so that fluid from the pressure chamber may flow toward the interrupting chamber to eifeot the extinction of the arc therein, biasing means for biasing both contact means to the closed circuit position, disconnect means, hydraulic operating means for effecting opening of the contact means against the biasing action exerted by the biasing means, means whereby the disconnect means causes operation of the hydraulic operating means, and passage means interconnecting the hydraulic operating means with the pressure-generating chamber to assist low current interruption so that liquid may flow sequentially toward the pressure-generating arc and subsequently onwardly through said firstmentioned passage means to the interrupting arc.

20. In a circuit interrupter or the liquid break type, contact means separable to establish a serially related pressure-generating arc and an interrupting arc, passage means interconnecting the two arcs so that liquid under pressure may flow from the pressure-generating arc toward the interrupting arc to effect the extinction of the latter, means biasing the contact means towards the closed circuit position, disconnect means, hydraulic operating means, means whereby the disconnect means causes charging motion of the hydraulic operating means during the closing stroke of the interrupter, and passage means interconnecting the hydraulic operating means with the two arcs so that liquid under pressure may flow, at least during low current interruption, from the hydraulic operating means toward the pressure-generating arc and subsequently onwardly through said passage means toward the interrupting arc.

21. In a circuit interrupt of the liquid break bring a pair of serially rein a body 0 quid, for electrically interconin a closed circuit position, J. in errnediate ends of the actuation oi the i t to draw simultan ously pressure and interrupting arcs, hydraulic means disposed at the upper ends of the units, offste ding actuating arm secured to and movable with the lift red, the cross-bar interposing two isolating gaps in the fully open circuit position of the interrupter, and the actuatarin causing operation of the hydraulic means prior to closing of the electrical circuit through the interrupter to thereby effect part charging of the hydraulic means before closing of the electrical circuit.

WINTHROP 1V1. LEEDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,934,454 Spurgeon Nov. '7, 1933 2,071,185 Thumim Feb. 16, 1937 2,155,263 Flurscheim Apr. 18, 1939 2,419,446 Flurscheim Apr. 22, 1947 2,459,599 Strom Jan. 18, 1949 2,463,029 Fry Mar. 1, 1949 2,%65,2 i0 Leeds Mar. 22, 1949 FOREIGN PATENTS Number Country Date 486,050 Great Britain May 30, 1938 500,731 Great Britain Feb. 13, 1939

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