US2739206A

US2739206A - Circuit breaker blast-valve mechanism

Info

Publication number: US2739206A
Application number: US321448A
Authority: US
Inventors: Fritz E Florschutz; Raymond H Leitzel
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1952-11-19
Filing date: 1952-11-19
Publication date: 1956-03-20
Anticipated expiration: 1973-03-20
Also published as: FR1090854A

Description

March 1956 F. E. FLORSCHUTZ ET AL CIRCUIT BREAKER BLAST-VALVE MECHANISM Filed Nov. 19, 1952 4 Sheets-Sheet l WITNESSES: 82 INVENTORS Fritz E.'Florschufz '6 ondg oymond H. Leitzel. 1? M WAW March 1956 F. E. FLORSCHUTZ ET AL ,739,206

CIRCUIT BREAKER BLAST-VALVE MECHANISM Filed Nov. 19, 1952 4 Sheets-Sheet 2 Fig.2. Q 50 39 & 12

G i v 44 l7 Ciosed Position Open Position 29 WITNESSES: INVENTORS c "(z E.Florschutz W- on oymond H.Leitzel zaam BY 4 fi ATTORNE March 20, 1956 F. E. FLORSCHUTZ ET AL Filed NOV. 19, 1952 4 Sheets-Sheet 3 3 Y Q 8| 79 YHI "/7 f I I til 58 30 32 Closing Operation L6 & 28 I a Fig.5.

7O Adjustment Position WITNESSES: 29 INVENTORS 2 Fritz E.Florschutz I aw 2 and Raymond H.Leitzel.

March 1956 F. E. FLORSCHUTZ ET AL 2,739,206

CIRCUIT BREAKER BLAST-VALVE MECHANISM Filed Nov. 19, 1952 4 Sheets-Sheet 4 Fig.8.

50 hsz WITNESSES: INVENTORS Frfiz E.Florschutz and Raymond H.Leitze|.

United States Patent i CIRCUIT BREAKER BLAST-VALVE MECHANISM Fritz E. Fiorschutz and Raymond H. Leitzel, Pittsburgh, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pin, a corporation of Pennsylvania Application November 19, 1952, Serial No. 321,448

3 Claims. (Cl. 200-148) This invention relates generally to circuit interrupters, and, more particularly, to blast-valve mechanisms therefor.

A general object of our invention is to provide an improved and more effective blast-valve mechanism for a circuit interrupter of the compressed-gas type.

A more specific object is to provide an improved blastvalve mechanism which may be readily adjusted during actual service conditions while the interrupter is in its cell or cubicle, Without necessitating a disassembly of the blast-valve mechanism components.

Still a further object is to provide an improved blastvalve mechanism in which valve adjustment may be easily made, and in which an automatic locking device is incorporated.

Still a further object is to provide an improved blastvalve lever assembly for a blast valve of a compressedgas circuit interrupter, in which an improved cam-roller lever is incorporated.

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

Fig. l is a fragmentary side elevational view, partially in section, of a compressed-gas circuit interrupter incorporating our invention, and shown in the closed-circuit position;

Fig. 2 is an enlarged, fragmentary, vertical sectional view through the blast-valve mechanism, showing the position of the parts in the closed-circuit position of the interrupter;

Fig. 3 is a view similar to Fig. 2, but indicating the position of the several parts during the opening operation when the blast valve is forced open;

Fig. 3A is an enlarged, fragmentary, detail sectional view taken along the line IlIA--IIIA of Fig. 3, looking in the direction of the arrows;

Fig. 4 is a view similar to Figs. 2 and 3, but indicating the position of the several parts during the closing operation when the cam-roller lever is moved to the inoperative position, the blast valve thereby remaining closed;

Fig. 5 is a view similar to Figs. 2-4, but indicating how the amount of blast valve opening may be adjusted during actual service conditions, without necessitating disassembly of the component parts of the blast-valve mechanism;

Fig. 6 is a top plan view of the blast-valve lever assembly;

ig. 7 is an end elevational view of the blast-valve lever assembly;

Fig. 8 is an enlarged sectional view taken along the line viii-VIII of Fig. 4; and

Fig. 9 is a plan view of our improved locking clip.

Referring to the drawings, and more particularly to Fig. 1 thereof, the reference numeral 1 generally designates a circuit interrupter of the compressed-gas type having a storage tank 2, which contains a suitable arcextinguishing gas, such as compressed air, under pressure, say for example around 150 pounds per square inch.

Controlling the flow of compressed gas from the storage tank 2 to the arc chute 3 is a blast-valve mechanism, generally designated by the reference character 4.

Pneumatically interconnecting the top of the blast-valve mechanism 4 with the arc chute 3 is an insulating blast tube 5, which preferably serves as a support for a terminal bracket 6, to which an external line connection may be made. Preferably the terminal bracket 6 is clamped about the insulating blast tube 5 and serves to pivotally mount a generally C-shaped movable contact 7. The movable contact 7 cooperates with a stationary contact 8, the latter being electrically connected to a terminal plate 9. As shown in Fig. 1, the external circuit connections are made to the interrupter 1 by means of the terminal plate 9 and the terminal bracket 6. insulating supporting rods 10 may be employed to provide additional support for the arc chute 3.

During the opening operation, the movable C-shaped contact 7 separates laterally away from the stationary contact 8 to establish an arc, not shown, across the upper open end of the blast tube 5. Simultaneously, in a manner hereinafter described, the blast-valve mechanism 4 functions to admit a blast of compressed gas from the tank 2 upwardly through the blast tube 5 and against the arc. The are is forced upwardly by the blast of gas into the arc chute 3, which may include a plurality of spaced slotted insulating plates, as set forth in U. S. Patent 2,272,380, issued February 10, 1942, to Leon R. Ludwig, Herbert L. Rawlins and Benjamin P. Baker, and assigned to the assignee of the instant application.

Functioning to move the movable contact 7 about its pivot connection 11 with the bracket 6, is an insulating operating rod 12. The upper end of the rod 12 is connected by a pin 13 to the movable contact 7. The lower end of the rod 12 is pivotally connected by a pin 14 to an actuating cam plate 16, which may be secured, as by welding, to an operating shaft 17. The operating shaft 17 extends laterally across the circuit interrupter 1, which may be of the multipole type. That is, the circuit interrupter 1 may control two or more phases of a multiphase circuit, and may have two or three blast tubes 5 and are chutes 3, associated therewith. There is provided an insulating operating rod 12 for each pole of the interrupter to cause the respective actuation of its movable contact. Consequently, since all of the operating rods 12 are connected to rotatable cam plates 16, which are all fixedly secured to the rotatable shaft 17, the mov able contacts 7 are all arranged for simultaneous motion.

To effect opening and closing rotation of the operating shaft 17 there is provided an operating lever 19, secured, as by Welding, to the shaft 17, and having the free outer end thereof pivoted to a connecting rod 21 as by a pin 21. The connecting rod 20 is connected to a piston, not shown, which moves axially within a piston cylinder 22.

Suitable valves

23, 24, which form no part of our invention, control the admission of compressed gas from the tank 2 through

conduits

18, 25, 26 to opposite ends of the operating cylinder 22. Thus, actuation of the valve 23 may serve to admit fluid through the

piping

13, 25 and 25 to the top end of the pneumatic cylinder 22, which will force the piston disposed therein downwardly in the opening direction. This downward movement of the piston causes downward movement of the connecting rod 28, and, through the operating lever 19, counterclockwise opening rotative motion of the operating shaft 17 and the several cam plates 16.

Reference may now be had to Figs. 2-9 to understand the operation of our improved blast-valve mechanism 4. Fig. 2 shows the position of the several parts of the mechanism 4 in the closed circuit position of the interrupter, as indicated in Fig. ,1. It will be noted that there is provided a valve casing 27, which may be secured by Patented Mar. 20, 1956' I more clearly shown in Fig. 9 of the drawings.

3. bolts 28 to an apertured flange portion 29 of the tank 2. Disposed interiorly within the valve casing .27 is a valve support 30, which serves to guide a blast valve, generally designated by the reference numeral 31. The

blast valve 31 includes a cap 32 and a spacer 33 which are held against a shoulder 3-! of the valve stem 35 by means of a castellated nut 36. A cotter pin 37 prevents the nut 36 from loosening.

Disposed between the spacer 33 and the cap 32 is a valve disk 38 formed of a suitable gas-tight material, such as rubber, and backed by an annular backing plate 39. The blast valve 31 seats against an annular valve seat 41), which is preferably the lower extremity of the valve-support member 30.

As shown in Fig. 2, the valve-support member 30 may be bolted by bolts 63 to the upper end of the valve casing 27. The valve-support member 38 also has integrally formed therewith a valve-stern guide 41, having a guide portion 42, which also serves as the lower seat for a compression spring 43, the latter serving to bias the blast valve 31 to the closed position, as shown.

The upper end of the compression biasing spring 43 seats against the end of a sleeve 44, which surrounds the upper end of the valve stem 35.

Disposed above the sleeve 44 is a locking clip 45, As shown in Fig. 9, the locking clip 45 has a locking projection 4-6, which slides within a slot 47 of the stem 35, as more clearly shown in Pig. 8 of the drawings. The loosing clip 45 prevents rotation of the valve stem 35 once adjustment of the upper threaded end 48 of the valve stem 35 has been made relative to the pivot pin 49. The pivot pin 49 extends between the legs SE) of a substantially box-shaped blast-valve lever casting 51, more clearly shown in Figs. 6 and 7 of the drawings.

The legs of the casting 51 have apertures 52 provided therethrough, through which extends the pivot pin 49, as shown in Fig. 8.. The pivot pin 49 has an aperture 52a provided therethrough, which is internally threaded, and within which is adjustably threaded the upper end 48 of the valve stem 35, as more clearly shown in Figs. 2 and 8 of the drawings.

The box-shaped blast-valve lever casting 51 is provided with an upper cover portion 53 and a lower web portion 54. As more clearly shown in Fig. 6, the casting 51 has apertures 55 provided in the

side walls

56, 57 thereof, through which extends a pivot pin 58. The pivot pin 53 serves to pivotally support the blast-valve lever assembly 59, including the casting 51, to a bifurcated lug portion 60 of the valve-support member 3i). Consequently, as readily shown in Pig. 3 of the'drawings, during the opening operation the operating shaft 17 and the actuating cam plate 16 rotate in counterclockwise direction, causing a cam follower 61, pivotally mounted at 62, on the lever assembly 59, to cause clockwise rotation of the same about the pivot pin 58 to effect opening of the blast valve 31, as shown. The cam follower 61 includes a cam-roller lever 64, which, as more clearly shown in Fig. 7 of the drawings, has the legs 65 thereof apertured, as at 66, to receive the pin 67 and the cam-roller 68. Flange portions 69, integrally formed with the casting 5'1 serve as stops for the legs 65 of the cam-roller lever 64, which is biased in a clockwise direction about the pin 62 by a compression spring 71 en circling a spring-guide rod 72. Que end of the springguide rod 72 projects through an aperture 73 (Fig. 6) provided in a flange or lip portion 74 of the casting '51. The ot er end of the spring-guide rod 72 is apertured to receive a pin 75, which pivotally interconnects the spring guide rod 72 with a bifurcated lug portion 76 of the cam roller lever 64, as more clearly shown in Fig. 7 of the drawings.

During the closing operation of the interrupter, that is during clockwise rotation of the operating shaft 17 and cam plate 16, it is desirable to maintain the blast valve 31 closed to conserve the supply of compressed gas. During such a closing operation, as indicatedin Fig. 4 of the drawings, the cam roller lever 64 is moved, against the biasing action of the compression spring '71, to an inoperative position. When the trailing edge 77 of the cam 78 of the cam plate 16 has moved past the cam roller 68, the spring 71 will cause clockwise rotation of the cam-roller lever 64 about the pivot pin 62 until the stops 69 engage the legs 65 of the lever 64-. Thus, in the fully closed circuit position of the interrupter, as illustrated in Fig. 2, the cam-roller lever 64 is against reset and in its operative position, ready to be engaged by the cam 78 during a subsequent opening operation.

As mentioned, there may be three pairs of contacts 7, 8 and three blast-valve mechanisms 4 associated with a single multi-pole circuit interrupter 1, which has a single operating shaft 17 associated therewith. Thus, in order to have the same quantity of gas flowing across the upper end of each of the blast tubes 5, a fine adjustment of the amount of opening of each blast-valve mechanism 4 is desirable. Actually, the blast valve 31 may open only a small distance, say, for example, three-fourths of an inch, and to coordinate all of the blast valves to insure their opening the same amount even though irregularities of the breaker parts may be present, is quite a problem.

With our improved blast-valve mechanism 4, a fine adjustment is possible by the threaded engagement of the upper end 48 of the valve stem 35 with the pivot pin 49. To enable this adjustment to be made while the blast-valve mechanism 4 is in the cell, and without necessitating disassembly of the mechanism, we have provided an improved arrangement, as more particularly brought out in Fig. 5 of the drawings. As illustrated in Fig. 5, to change the adjustment of the blast valve opening it is merely necessary to remove the pivot pin 58, pivotally connecting the lever assembly 59 to the valvesupport member 3 6 at the lug portion 6%, and swing the lever assembly 59 about, as shown in Fig. 5. During this movement the gas pressure, as represented by the arrows 7!), acting upon the blast valve 31 prevents the same from rotating. During the rotation of the lever assembly 59 to the position shown in Fig. 5 a pair of releasing projections 79 (Fig. 6) move over the locking clip 45 and force the same downwardly to a released position, as shown in Fig. 5. The lever assembly 59 is then rotated about the axis of the valve stem 35 until the desired amount of blast valve opening is obtained. Following adjustment and return of the lever assembly 59 to the position shown in Fig. 2, and reinsertion of the pivot pin 58, the locking clip 45 will be automatically forced outwardly by the spring 43 so that it is again maintained in a locking position between the lower sides of the legs 50 of the casting 51, as shown more clearly in Fig. 8 of the drawings. This maintains the adjustment of the amount of valve opening.

During the foregoing adjustment of the amount of blast-valve opening, it will be apparent that the effect of such adjustment is to rotate cam roller 68 in an are about the pivot axis 58. This will change the time at which the cam 78 engages the cam roller 6%. Readjustment of the cam 78 may then be necessary, as explained hereinafter.

Fig. 3A shows the adjustable relation of the cam '78 with respect to the cam plate 16. As shown, both have serrations 82. An elongated slot 33 is provided in the cam 78 through which two locking bolts 84 extend to thread into tapped openings 85 in the cam plate 16. Hence to vary the timing at which the cam 78 engages the cam roller 68 relative lateral motion between the cam 73 and the cam plate 16 is possible.

It will be observed that because of the pivotal connection between the valve stem 35 and the pivot pin 49 there is only required a single short guide portion 42 near the blast valve 31. Also, because of the considerable bearing area between the upper end 48 of the valve stem 35 and the pin 49, and between the pin 49 and the apertures 52 of the legs 50, there is no need for heattreated parts. Thus, a clearance 80 about the sleeve 44 is provided.

From the foregoing description of our improved blastvalve mechanism it will be apparent that we have provided a mechanism capable of fine adjustment of valve stroke and automatically released and locked during the adjustment operation. The threads on the valve stem 35 may be fine to assure a close adjustment. Also, by the particular construction of the biasing means 71 for the cam-roller lever 64, we have conserved space and yet have provided a trouble-free construction. As indicated in Fig. 4, during the rotation of the cam-roller lever 64 to the inoperative position, the end 81 of the springguide rod 72 extends between the legs 50 of the casting 51 and over the end 48 of the valve stem 35. This construction is simple, compact and provides a trouble-free service condition.

Although we have shown and described a specific structure, it is to be clearly understood that the same was merely for the purpose of 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 invention.

We claim as our invention:

1. A circuit interrupter of the compressed-gas type wherein a blast valve is pivotally connected to a blastvalve lever assembly, characterized by the fact that the blast-valve stem is threadedly secured to the pivot pin of the blast-valve lever assembly, and a locking clip for maintaining the adjustment when once made, said locking clip being maintained against rotation by the blastvalve lever assembly.

2. In a circuit interrupter of the compressed-gas type wherein a blast valve controls the flow of compressed gas to the arc chute, and wherein the blast valve stem is threadedly secured to the pivot pin of the blast-valve lever assembly, the combination with said stem of a locking clip and a leg portion associated with the blast-valve lever assembly for maintaining the locking clip and valve stem against rotation.

3. In a circuit interrupter of the compressed-gas type wherein a blast valve controls the flow of compressed gas to the arc chute, and wherein the blast valve stem is threadedly secured to the pivot pin of the blast-valve lever assembly, the combination with said stem of a locking clip and a leg portion associated with the blast-valve lever assembly for maintaining the locking clip and valve stem against rotation, and one or more releasing projections movable with the leg portion to release the locking clip upon rotation of the blast-valve lever assembly about the pivot pin.

References Cited in the file of this patent UNITED STATES PATENTS 2,266,081 Rogers -2 Dec. 16, 1941 2,282,154 Bakken May 5, 1942 2,404,210 Bechler July 16, 1946 2,456,965 Leitzel Dec. 21, 1948 2,567,735 Scott Sept. 11, 1951