US2495156A - Circuit interrupter - Google Patents

Description

Jan. 17, 1950 B. P. BAKER 2,495,156

CIRCUIT INTERRUPTER Filed Dec. 15, 1945 s sh ts-sheet 1 .slls or WITNESSES: INVENTOR Jan. 17, 1950 B. P. BAKER 2,495,156

CIRCUIT INTERRUPTER Filed Dec. 15, 1945 a SheetsSheet 2 INVENTOR Benjamin Pfia ker. @4 4 21/ ATTORN WITNESSES:

Jan. 17, 1950 B. P. BAKER 2,495,156

CIRCUIT INTERRUPTER Filed Dec. 15, 1945 3 Sheets-Sheet 3 WITNESSES: INVENTOR f%4 .Ben/am/h Ego/(er. Z. q 7 W Patented Jan. 17, 1950 CIRCUIT INTERRUPTER.

Benjamin P. Baker, Turtle Creek, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 15, 1945, Serial No. 635,353

13 Claims.

This invention relates to circuit interrupters in general and, more particularly, to arc-extinguishing structures and contact arrangements therefor.

A general object of my invention is to provide an improved circuit interrupter which will not have its opening operation impeded by ice or snow incrustation at the contact structure.

A more specific object of my invention is to provide an improved circuit interrupter of the gas-blast type in which a portion of the opening gas or air is utilized to effect separating motion of a pair of contacts.

Another object is to provide an improved circuit interrupter of the gas-blast type incorporating a pair of arcing contacts and a pair of serially related disconnect contacts in which opening air is employed not only to assist in separating motion of the disconnect contacts but also is utilized to assist in extinguishing the residual current are drawn at the disconnect contacts.

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 of a gas-blast type of circuit interrupter embodying my invention and shown in the closed circuit position;

Fig. 2 is an enlarged substantially vertical sectional view taken along the line IIII of Fig. 1;

Fig. 3 shows a modified type of contact structure incorporating my invention;

Fig. 4 shows still another modified type of contact structure incorporating my invention.

Fig. 5 is a vertical sectional view partially in elevation taken along the line V-V of Fig. 4;

Fig. 6 is a plan view of a modified type of disconnect contact structure; and

Fig. 'I is a sectional view taken along the line VII-VII of Fi 6.

Referring to the drawings and more particularly to Fig. 1 thereof, the reference numeral l designates a base formed of structural steel which supports in place a tank 2 of compressed gas, in this instance air. Supported on top of the base I are three insulator columns, only two of which appear in Fig. 1, and are respectively designated by the reference numerals 3, 4. The three insulator columns support a mechanism housing 5, which encloses a suitable pneumatic mechanism, not shown, for causing separating upward pivotal movement of a blade-shaped movable disconnect 2 structure generally designated by the reference numeral 1, and shown more clearly in Fig. 2.

The mechanism housing 5 supports an insulator column 8 at the upper end of which is supported an arc-extinguishing structure, generally designated by the reference numeral 9. Disposed within the arc-extinguishing structure 9 are two serially related movable arcing contacts l0, II which are simultaneously separable from a conducting plate l2.' Two insulating plates l3, H are spaced by tubular spacers l5 which extend through the insulating plates l3, It, as well as through the conducting plate 12. Thus, it is possible for arc-extinguishing gas in the region It to pass upwardly through the tubular spacers l5 into the region H.

The movable arcing contacts II), II are respectively secured to piston members l8, is which are.

movable in piston chambers 20, 2|. The pistons I8, is are respectively biased by compression springs Ha, Ha to the closed position shown in Fig. 1. The piston chamber 20 comprises a conducting tube having an annular gas conducting space between it and the inner wall of the insu- Y lator column 8. The opposed inner ends of the piston chambers 20, 2| serve to direct compressed gas through orifices 22, 23, provided in the insulating plates l3, H. The compressed gas after passing through the orifices 22, 23 vents radially outwardly between the insulating plates I3, I and the conducting plat [2. Suitable cooling means, not shown, may be provided to cool the ionized arc gases before they leave the arcextinguishing structure 9 through the louvers 24.

The sequencing within the mechanism housing 5 is such that the movable disconnect contact 8 does not pivotally move upwardly until the arcs drawn within the arc-extinguishing structure 9 are fully extinguished.

Extending upwardly from the arc extinguisher 9 is an insulator column 25 which supports the line terminal 26 of the interrupter. The'stationary disconnect contact structure I is supported at the upper end of an insulator column 21, in the interior of which is disposed suitable metering equipment. At the top of the insulator column 21 is secured the right-hand line terminal 28 of the interrupter.

From the foregoing description, it will be apparent that in the closed circuit position of the inter rupter, as shown in Fig. 1, the electrical circuit therethrough includes the line terminal 25, conducting piston chamber 2l, movabl arcing contact ll, conducting plate l2, movable arcing concontaot 6 from a stationary disconnect contact mm; lo, nd tin l t chamber 39, by suitable housing 5.

. drawn within 3 connector means, not shown, to the movable disconnect contact 6. The circuit then extends through the stationary disconnect contact structure l and through metering equipment disposed within the insulator column 21 to the right-hand line terminal 28 of the interrupter.

To eflect the opening operation of the interrupter, valve structure 29 is actuated to permit an opening blast of gas to pass from the manifold 3|) upwardly through the valve housing 3| and upwardly through the insulator column 3 to the pneumatic mechanism disposed within the The blast of gas passes through suitable conduit means provided within the interior of the housing 5 and upwardly around the piston chamber 20. The opening blast of gas then passes into the region l6 and upwardly through the tubular spacers It to the region II. The compressed gas within the regions l6, l1 acts upon the piston members l3, is to force them and consequently the movable arcing contacts I, II apart to draw two serially related arcs extending between the tips of the arcing contacts and the conducting plate l2.

The compressed gas within the regions l6, l1 passes through the orifices 22, 23 eilfecting extinction of the two serially related arcs therein to vent radially outwardly out of the arc-extinguishing structure 9 between the insulating plates |3. l4 and the conducting plate l2.

Following interruption of the two serially related arcs the pneumatic mechanism disposed within the housing 6 is actuated to cause pivotal counterclockwise rotation of the movable disconnect contact 6 upwardly away from the stationary disconnect contact structure 1. Following separation of the disconnect contacts 6, 1, suitable means, not shown, may be provided to close the valve structure 29 to cease the upward passage of gas from the manifold 30. At this time the springs Ila, Isa will close the arcing contacts III, II.

Impedance means in two resistors this instance including 32, 33 shunt the are which are the arc extinguisher 9. More specifically, the resistors or impedance means 32, 33 have a tap connection 34 leading to the conducting plate l2. The resistor 32 has a lead 35 connected to the line terminal 26. The resistor 33 has a connector 36 terminating at the metallic housing 5. Consequently, the impedance means which 1 provide to shunt the arcing contacts IO, N permits a residual current to pass therethrough following are interruption, which residual'current must be interrupted at the disconnect contacts 6, I. If the impedance means 32, 33 is not employed, the disconnect contact structure need not open any current whatsoever,

the circuit being entirely broken at the arcing contacts III, II within the arc extinguisher 6. A conduit 31 connects with the blast tube 38 and is coupled by a coupling 39 to a ceramic tube 40 which extends upwardly through the interior of the insulator column 21 to the stationary disconnect contact structure 1.

Referring to Fig. 2, which shows more clearly than Fig. 1, the construction of the stationary disconnect contact structure I, it will be observed that the stationary disconnect contact structure I is of the jaw type including two opposed finger contacts 4|, 42 of right-angle construction, which are bolted at their ends by bolts 43 to a dish-shaped metallic member 44 which also supports a metallic diaphragm 45, a gasket 46' being employed to prevent gas leakage. It will be obwill be observed that iii) served from the foregoing description that should the contact structure 6, 1 be incrusted with ice formation, the passage of gas upwardly through the conduit 4|) during the opening operation will cause upward flexing of the diaphragm to cause a slight separating pivotal movement of the stationary disconnect fingers 4|, 42 to eilect release of the movable blade-shaped disconnect contact 6.

It will be observed that with the construction shown, the operation of the diaphragm 45 is not impeded by any ice formation at the contact structure. It will also be observed that considerable torque action takes place to thereby bring into play large forces in causing separation of the disconnect contacts.

In the modified type of stationary disconnect contact structure 41 shown in Fig. 3, it will be observed that a block 48 is secured as by welding to the center of the diaphragm 46. The stationary disconnect finger contacts 4|, 4Lare pivotally mounted at 49, 66 to the block 48. The lower ends of the stationary disconnect fingers 4|, 42 have offstanding lug portions ii to which are riveted flexible straps 62 carrying the current by means of the bolts 43 to the dish-shaped metallic member 44.

From the aforesaid construction it will be apparent that the passage of opening gas through the conduit 40 will cause upward flexing motion of the diaphragm 45 to take place, which will cause outward separating motion of the disconnect fingers 4|, 42. The upper ends of the disconnect flngers 4|, 42 are pivotally connected at 53, 64 to spring guide rods 66, 68, the lower ends of which pass through apertures 51 provided in lug portions 58 or the member 44. A compression spring 59 encircles each spring guide rod 85, 56 and serves to supply contact pressure in the closed position, as shown in Fig. 3. During the opening operation, the rods 55. 66 cooperate with nuts 60, secured to the lower ends thereof, to limit the inward motion of the stationary disconnect fingers 4|, 42.

In the construction shown in Figs. 4 and 5, it

I have not only used a portion of the opening gas to efiect release of the disconnect contact structure, but have also utilized a portion of said gas to assist in extinguishing the residual current arc drawn at the disconnect contact structure should impedance means 32, 33 be employed shunting the main arcing contacts III, II. Thus, the conduit 40 has connected thereto a conduit 6| which has its end 62 so directed as to direct opening as or air adjacent the separating disconnect contacts to assist in extinguishing the residual current are drawn between the movable disconnect contact 6 and the stationary disconnect contact fingers 4|, 42. Preferably, a flap valve 62a is biased by a leaf spring 62b against a ing portion 620 of the grind-nit 6| to prevent rain entering the conduit Bracket means 63, in this instance consisting relate flexing motion of the diaphragm 45 with separating motion of the stationary disconnect contact fingers 4|, 42. The right-angle brackets 64 are secured by bolts 65 to the supporting structure 66 and have side portions 61 resting against the face of the diaphragm 45. The other side 68 of the right-angle bracket 64 has an aperture 68 provided therethrough through which extends a rivet 10 having a head 1|. The rivet I0 is secured to the disconnect fingers 4|, 42 and serves to cause the disconnect fingers 4|, 42 to be moved apart upon flexing of the right-angle bracket 54 in response-to flexing of the diaphragm 45. In this construction, it will be noted that the contact fingers 4 I, 42 stand out and are well drained. It will also be noted that the flexing of the diaphragm 45 causes separating motion of the stationary disconnect fingers 4|, 42 to effect releasement between the movable and disconnect contacts even though ice may be incrusted thereat.

In the modified type of stationary disconnect contact structure 12 shown in Figs. 6 and 7 it will be observed that the conduit 40 leads into a cup-shaped member I3 having an annular deflector 14 secured, as by welding, to the upper end thereof. The metallic diaphragm 45 has a rod 15 secured to the center portion thereof as by welding. To the lower end of the rod 15 is secured a spider 16 which serves as a lower seat for a compression spring 'll, the upper end of which seats against an inwardly extending flange I8 secured as by welding to the interior face of the cup-shaped member 13.

Preferably, flexible shunts 19 are employed to electrically interconnect the spider 16 with the flange 18 to carry the current of the disconnect contacts. The blade-shaped movable disconnect contact 6 again slides between the stationary disconnect finger contacts 4|, 42 which have portions 80 seated nearer the center portion of the diaphragm 45. The stationary disconnect finger contacts 4|, 42 have horizontal portions 81 which are secured by screws 82 to a ring 83 which is secured to the diaphragm 45 by any suitable means, such as by brazing. It will be noted that the metallic diaphragm 45 seats upon a gasket 84 disposed in an annular groove 85 provided at the upper end of the cup-shaped member 13.

The opening of the modified type of stationary disconnect contact structure 12 will now be described. Following the "opening of the arcing contacts II], I l to interrupt the main circuit passing through the interrupter, there still remains a residual current which passes through the resistors 32, 33 and consequently through the movable and stationary disconnect contact structure including the flexible conductors 19. The upward passage of opening air through the conduit 40 strikes the metallic diaphragm 45 to cause a deflection of the same, thereby flexing the stationary disconnect contact fingers 4|, 42 outwardly to break any ice formation incrusted' thereat. Following the deflection of the metallic diaphragm 45 to efiect opening of the disconnect contact structure, the air pressure further acts over the entire surface of the ldiaphragm 45 to bodily raise the same upwardly away from the gasket 84 against the downward biasing action exerted by the compression spring 11. After the diaphragm 45 together with the stationary disconnect contact fingers 4|, 42 has raised, the air is then permitted to pass around the diaphragm 45 and to be deflected by the deflector 14 to extinguish any residual current are which is drawn between the movable bladeshaped disconnect contact and the stationary disconnect contact fingers 4|, 42. Thus, it will be observed that in this embodiment of my invention the directing of the gas flow about the diaphragm 45 is readily obtained to effect a rapid extinction of the residual current are drawn at the disconnect contact structure.

From the foregoing description it will be apparent that I have provided an improved outdoor compressed gas circuit interrupter which prevents the incrustation of ice at the disconnect contact structure from interfering with the operation of the disconnect contacts. I have accomplished this by utilizing diaphragm means which is acted upon by a portion of the opening air fed from the blast tube 38. Also, I have shown a means whereby not only is the opening air utilized to effect separation of the disconnect contact structure, but it is also used to help extinguish the residual current are drawn at the disconnect contact structure should impedance means 32, 33 be employed to shunt the main arcing contacts Ill, II. The concept of utilizing opening air to effect extinction of the residual current are at the disconnect contact structure is described and claimed in the United States patent application, Serial No. 624,284, filed October 24, 1945, by Benjamin P. Baker and Oswald von Mehren, and assigned to the assignee of the instant application.

It will also be noted that I have provided an improved contact structure which is applicable not only to circuit interrupters of the outdoor compressed gas type, but is also applicable to any type of circuit interrupter where because of weather conditions ice may be formed at the contact structure. By an application of my invention to such a type of circuit interrupter, releasing of the contact structure against friction and corrosion even though ice or snow may not be present is obtained to thereby bring about rapid contact separating motion.

Although I have shown and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration and that changes and modifications may be readily 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, a stationary jawshaped contact including two opposed finger contacts, a movable contact cooperating with said finger contacts, a diaphragm, a block secured to the center of the diaphragm, the two finger contacts being pivotally mounted to the block, and means for applying gas pressure to one side of the diaphragm to flex said diaphragm to move said finger contacts away from said movable contact.

2. In a circuit interrupter, a movable bladeshaped contact, a jaw-shaped contact including two opposed finger contacts, a diaphragm, bracket means mounted against the diaphragm, means interconnecting the bracket means to the finger contacts, means applying gas pressure to one side of the diaphragm, and the flexing of the diaphragm causing through the bracket means separating motion of the finger contacts.

3. In a circuit interrupter of the gas-blast type, a pneumatic operating mechanism, a pair of arcing contacts, serially related disconnect contacts comprising a movable contact and opposed stationary contacts engaging said movable contact, impedance means shunting the arcing contacts, means comprising a diaphragm flexed by opening gas and disposed to efiect separating movement of said opposed contacts to release said movable contact, and means employing opening gas to assist in interruption of the residual current are established at the disconnect contacts.

4. In a circuit interrupter of the gas-blast type, a pneumatic operating mechanism, a pair of arcing contacts, serially related disconnect contacts comprising a pair of opposed stationary contacts and a movable contact, a diaphragm operable to move said opposed stationary contacts away from said movablecontact, means permitting opening gas to act on one side of the diaphragm to flex said diaphragm, and means interrelating flexing of the diaphragm with separating motion of the disconnect contacts to eiIect movement of said opposed stationary contacts away from said movable contact during the separating movement of said disconnect contacts.

5. In a circuit interrupter of the gas-blast type, a pneumatic operating mechanism, a pair of arcing contacts, serially related disconnect contacts comprising a movable contact and a pair of opposed stationary contacts, a diaphragm flexible to move said opposed stationary contacts away from said movable contact, means permitting opening gas to act on one side of the diaphragm to fiex said diaphragm, means interrelating flexing oi the diaphragm with separating motion of the disconnect contacts, impedance means-shunting the arcing contacts, and means employing opening gas to assist in interruption oi the residual current are established at the disconnect contacts. V

6. In a circuit interrupter, a movable contact, opposed stationary finger contacts resiliently embracing said movable-contact in the closed circuit position, and pneumatic means comprising a diaphragm operable during the opening operation to cause outward separating motion of the stationary finger contacts away from said movable contact to efl'ect release of the movable contact.

7. In a circuit interrupter, a movable contact cooperable with a stationary contact, a diaphragm, means permitting gas pressure to act upon one side of the diaphragm, means responsive to movement of the diaphragm to eifect releasing engagement between the stationary and movable contacts, and means for permitting a portion of s the gas to pass around the diaphragm to assist in eii'ecting the extinction of any are drawn at the contacts.

8. In a circuit interrupter, a. movable disconnect contact a diaphragm, a pair of opposed finger contacts having portions thereof resting against the face of the diaphragm, said finger contacts having other portions engaging said disconnect contact and means for applying gas pressure to the opposite face of the diaphragm during the opening operation to cause flexing thereof thereby resulting in outward separating motion of the pair of finger contacts to release said movable disconnect contact.

9. In a circuit interrupter, a cup-shaped member having a deflector secured to the upper end thereof, a diaphragm covering the upper end of 8 the cup-shaped member, means biasing the diaphragm to the closed position, a pair of finger contacts having portions thereof in abutting engagement with the upper face of the diaphragm, and means for applying gas, pressure to the diaphragm during the opening operation.

10. In a circuit interrupter, a movable contact stationary contact means comprising opposed contacts resiliently engaging opposite sides of said movable contact, diaphragm means in operative engagement with the stationary contacts, and means for applying gas pressure to the diaphragm means for flexing said diaphragm to eiiect releasing movement of said stationary contacts.

11. In a circuit interrupter, a movable contact cooperable with a stationary contact, diaphragm means in operative engagement with the stationary contact, means for applying gas pressure to the diaphragm means to elect release of the movable and stationary contacts, and means for permitting a portion of the gas to by-pass the diaphragm means to assist in eii'ecting the extinction of any are drawn at the contacts.

12. A circuit interrupter including a pair of opposed stationary contacts. a cooperating movable contact engageable between said stationary contacts, a diaphragm cooperating with said stationary contacts, and valve means for admitting fluid pressure to one side of said diaphragm to effect movement of said stationary contacts away from said movable contact to release said movable contact.

13. A circuit interrupter including stationary jaw-shaped contact means, a movable contact cooperating with said stationary contact means to open and close the circuit, fluid pressure operated means operable to move said stationary contact means away from said movable contact, fluid presure operated means for moving said movable contact to open position, and a valve for admitting fluid pressure to both of said pressure operated means.

BENJAMIN P. BAKER.

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

UNITED STATES PATENTS Number Name Date 1,582,154 Zeiher, et al Apr. 27, 1926 2,250,216 Biermanns July 22, 1941 2,306,186 Rankin Dec. 22, 1942 2,365,134 Amer, et a1. Dec. 12, 1944 2,379,761 Strang July 3, 1945

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