US2619356A - Valve mechanism - Google Patents

Description

NOV. 25, 1952 R, E FR1EDR|CH ETAL 2,619,356

VALVE MECHANISM Filed Feb. '7, 1950 Fig.2.

lnsuluhon `l 5 6 WITNES ES: INVENTORS f77/Z RobertEFriedrich a? i BOYnd Joseph Suche.

Patented Nov. 245', 195:2

VALVE MECHANISM Robert E. Friedrich, Pittsburgh, and Joseph Sucha, McKeesport, Pa.,

house Electric Corporation,

assignors to Westing- East Pittsburgh,

Pa., a corporation of Pennsylvania Application February 7, 1950, Serial No. 142,876

3 Claims.

This invention relates to valve mechanisms in general, and more particularly to a compact valve mechanism of the type having a dual function, namely, of serving as a check valve, closing at light pressures, and also serving as an overpressure valve opening at excessive pressures.

A more specific object is to provide an improved valve mechanism of the aforementioned dual functioning type for use in a circuit interrupter so as to close during light pressures and to open at excessive pressures.

In the construction of circuit interrupters, it is desirable to have a valve which will open upon the existence of excessive pressures within the circuit interrupter to prevent possible rupturing of the arc extinguishing unit. It is also desirable to have a valve which is normally open to permit the egress of collected gas and contaminated fluid out of the interrupter during static conditions, that is, when the circuit interrupters in the completely closed circuit position or in the completely open circuit position, which valve will close during the existence of relatively low pressures within the arc extinguishing unit to conserve the relatively low pressure for blasting fluid against the arc.

It is desirable in order to conserve space to provide a single valve mechanism which will have all of the above-enumerated functions and which will be simple, compact and easy to service. In United States patent application, filed February '7, 1950, by Roswell C. Van Sickle and Carl G. Lentjes, Serial No. 142,838, and assigned to the assignee of the instant application, there is disclosed a valve mechanism of the dual functioning type. It is an object of our invention to improve and simplify the valve mechanism in the aforementioned application.

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

Figure 1 is a side elevational view of a circuit interrupter, the tank being fragmentarily broken away in vertical section, embodying our invention and shown in the cloesd circuit position;

Fig. 2 is an enlarged side elevational view, partially in vertical section of the left-hand arc extinguishing unit of the circuit interrupter set forth in Fig. l, the contact structure being indicated in dotted lines and shown at an intermediate point in the opening operation. The relative position of the parts of the valve mechanismis shown during the existence of excessive pressures;

Fig. 3 is a fragmentary quarter sectional view taken along the lines III- III of Figs. 5 and 6, the relative position of the valve parts being that during the existence of relatively low pressures;

Fig. 4 also is a quarter sectional View taken along the line III-III of Figs. 5 and 6, similar to the view of Fig. 3, but indicating the relative p0- sition of the Valve mechanism parts during static conditions, that is, in the completely closed circuit position of the interrupter or in the completely open circuit position of the interrupter; and

Figs. 5 and 6 are detail plan views of the valve parts.

Referring to the drawing, and more particularly to Fig. l 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 a pair of terminal bushings 5, 6, to the lower ends of which are secured identical arc extinguishing units generally designated by the reference numeral 1.

The two units 'I are electrically connected in series by a conducting cross-bar 8, reciprocally actuated in a vertical direction by an insulating lift rod 9. The lift rod or operating rod 9 may be actuated by any suitable mechanism which forms no part of our invention. Disposed at the outer extremities of the conducting bridging member 8 are a pair of lower movable interrupting contacts I0 of rod-shaped configuration.

As shown more clearly in Fig. 2, which discloses the left-hand arc extinguishing unit 'I in side elevation with the upper portion of the unit I in vertical section, it will be apparent that the rod-shaped lower movable interrupting contact I0 strikes, in abutting engagement, an intermediate contact I2, and raises the latter until the intermediate contact I2 strikes a relatively stationary pressure-generating contact I3, pivotally mounted at I4 on a stationary pivot secured by a bracket I5 to a side plate I6 forming a part of the pressure-generating housing I'I. As shown, the pressure generating contact I3 is biased downwardly by a compression spring I8 and has a flexible conducting strap I9 bolted thereto, as at 20, to avoid the necessity of having the series current traverse the pivot point I4. An adjustable stop 2| limits the downward travel of the pressure-generating contact I3 so that further downward opening motion of the intermediate contact I2. as permitted by continued lowering opening motion of the interrupting con- 3 l tact l0, will establish a pressure-generating arc 22 within the pressure-generating chamber 23.

The intermediate contact I2 halts at a predetermined point in its opening motion, as indicated in Fig. 2, to establish an interrupting arc 2Q between the intermediate and interrupting contacts l2, l0. Pressure generated within the pressure-generating chamber 23 by the pressure-generating arc 22 acting upon the oil disposed therein, sends oil under pressure downwardly through suitable passage structure as indicated by the dotted arrows 25 so that the interrupting` arc 2f! is blasted by oil under pressure coming downwardly from the pressure-generating chamber 23. The particular configuration of the passage structure provided by the several plates 2E forms no part of our invention, and reference may be had to United States Patent 2,467,760, issued April i9, 1949, to Leon R. Ludwig, Benjamin P. Baker and Winthrop M. Leeds, and assigned to the assignee of the instant application. This patent discloses, in considerable particularity, the comiguration of the plates and goes into considerable theory concerning the manner of arc extinction.

For our purposes, it is only necessary to know that oil is sent under pressure from the pressure-generating arc 22 downwardly through suitable passages toward the interrupting arc 2d where the oil is then vented out of the arc extinguishing unit 'i through the lateral vent passages Z'i. Arc extinction soon follows and continued downward opening motion of the lower movable interrupting contact l inserts an isolating gap into the circuit. The dotted lines 28 of Fig. l indicate the fully open circuit position of the interruptor with the two movable interrupting contacts iii completely withdrawn from the two arc extinguishing units 'i thereby providing two disconnect gaps in the circuit.

Our improved valve mechanism will now be described. As indicated in Fig. 2, there is relatively little space within the pressure-generating housing Il for the disposition of a valve mechanism 25. This is particularly so in the case where a side operating rod is utilized to actuate the pressure-generating contact i3 so that the two arc 22, 26 are established practically simultaneously. This side operating rod construction is disclosed in the aforementioned United States Patent 2,457,760, and when it is used, there is even less space provided in the housing il than is shown in Fig. 2.

It is generally necessary to provide an overpressure valve and also a check valve. Heretofore, these two valve functions have been performed by separate valves which took considerable space within the wall dening the pressuregenerating chamber 23. The aforementioned patent application discloses one manner or solving the problem oi having a single valve mechanism provided with dual functions so that it will not only serve as an overepressuro valve, but will also serve as a check valve. Our invention is an improvement'over the valve mechanism described in the foregoing patent application, and preferably consists of a stationary control plate shown more particularly in Fig. 5, having a plurality or over-pressure apertures Si provided therethrough, and also a plurality ci low pressure relief ports disposed along its periphery, as clearly shown Fig. 5.

The control plate 3E is fixed in a stationary position by a bolt c3 upon which is threaded a nut Sii having a shoulder portion The shoulder portion e5 makes abutting engagement with the control plate 3G. The bolt 33 is accommodated by a central aperture 3B provided in the control plate 3B. The head 37 of the bolt 33 is disposed within a recess 58 formed within the top plate casting S9 of the pressure-generating housing l1. It will be observed that the casting 39 has a recess portion il formed therein together with a plurality of vent apertures fil. The periphery of the control plateY E8 fits within a shoulder recess 2 provided in the casting 3S.

An alignment pin 3 is threadedly secured to the control plate Si) within an aperture 44, as shown more clearly in Fig. 5. The alignment pin 33 makes sliding engagement within an aperture 5 formed in a low pressure check valve plate e6, the configuration of which is more clearly shown in Fig. 6 of the drawing. Referring to Fig. 6, it will be observed that the check valve plate has a plurality of over-pressure apertures si provided therein which make alignment, or which register, with the over-pressure apertures 3l of the control plate 3G. Also a central aperture is provided within the check valve plate i5 to accommodate the portion of the nut tl.

The downward motion oi the check valve plate i5 is limited by a stop portion Si) of the nut 3G, as shown more particularly in Fig. 4 of the drawing. The alignment pin i3 also keeps the apertures 3i, l or" the plates respectively, in alignment.

An over-pressure valve plate 5i of circular shape is provided having a single central aperture E2 formed therein to accommodate the shank portion of the stud bolt This over-pressure valve plate 5l covers the over-pressure apertures 3l or" the control plate 39, as shown in Figs. 3 and 4, being biased toward said position by biasing means, in this instance including a compression spring 53. The lower end of the compression spring 53 seats upon the top of the pressure valve plate 5l. The upper end of the compression spring 53 seats within a recess 5t' formed within the top plate casting 39.

The operation of our improved valve mechanism will now be described. In the fully open circuit position of the interrupter, as shown by the dotted lines 28 of Fig. l, or in the completely closed circuit position of the interruptor (not shown), the valve mechanism 29 assumes the position shown in Fig. 4, in which position co1- lected gas and contaminated oil may pass out of the unit 1 past the periphery of the check valve plate :it and through the low pressure relief ports 32 of the control plate 3l), as indicated by the arrow 55 of Fig. 4. The gas and contaminated oil may also pass through the low pressure relief ports 32 provided in the control plate 30, by way of the. over-pressure apertures nl? provided in the check valve plate lit. This latter course of the fluid is indicated by the arrow 56 of Fig. 4. It will be observed that in this static condition, as shown in Fig. 4, the over-pressure valve plate 5i closes the overpressure apertures 3| provided in the control plate 30. Consequently, from the foregoing, it is apparent that the improved Valve mechanism 29 is operative to vent the unit 'l during static conditions. Accumulated gas, say vfrom a. previous interruption, may hence pass freely out of the unit 'I and circulation of the oil through the valve mechanism 2S during such static conditions is facilitated.

During the existence of over-pressure conditions within the unit 1, that is, during the interruption of heavy currents where the pressuregenerating arc 22 generates excessive pressures, the valve mechanism 29 assumes the position as shown in Fig. 2 of the drawing. It will be observed that the check valve plate 46 has been forced upwardly into abutting engagement with control plate 30 and the pressure acting through the over-pressure apertures 41, 3| (which register) acts upon the exposed area of the overpressure valve plate 5| to raise the same upwardly against the downward biasing action exerted by the compression spring 53. Consequently, uid may exhaust out of the unit 1 by way of the over-pressure apertures 41, 3l, and past the periphery of the over-pressure valve plate 5l, as indicated by the arrows 51 of Fig. 2.

During the interruption of relatively light currents, where it is necessary to conserve the pressure so as to obtain the requisite quantity of huid under pressure directed toward the interrupting arc 24 to extinguish the same, the valve mechanism 29 remains closed, as indicated in Fig. 3. In other words, Fig. 3 indicates the relative position of the several parts of the valve mechanism 29 during the interruption of low currents where it is desirable to conserve the pressure. It will be observed that the pressure is too low to raise the over-pressure valve plate 5I against the biasing action exerted by the compression spring 53. It will, however, be noted that the pressure, even though slight, will be such as to easily raise the low pressure check valve plate 46 so that the portions 58 of the low pressure check valve plate 46 will close the low pressure relief ports 32 provided in the control plate 30. Thus, the valve mechanism 29 is completely closed, as shown in Fig. 3.

From the foregoing description of our improved valve mechanism, it will be apparent that we have provided an improved compact valve mechanism which may be easily serviced and which requires very little space. It will also be observed that the valve mechanism 29, although normally open, closes at slight pressure, thereby serving as a check valve, and opens upon excessive pressure, thereby serving as an overpressure relief valve. The parts are few and simple. It will also be observed that by diminishing the size of the over-pressure apertures 41, 3i of the plates 46, 30, respectively, the exposed area of the over-pressure valve plate 5l to the high pressure may be reduced, and consequently the spring pressure 53 need not be excessive.

Certain features of our valve mechanism are of general application and not exclusively applied to circuit interrupters. Merely for purposes of illustration have we illustrated its use in a circuit interrupter.

Although we have shown and described a specic structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the appended claims.

We claim as our invention:

l. A normally open valve mechanism including e. relatively stationary control plate, the control plate having one or more over-pressure apertures and one or more low pressure relief ports, an over-pressure valve plate disposed on one side of the control plate and covering only the one or more over-pressure apertures while leaving the low pressure relief ports exposed, means biasing the over-pressure valve plate to its closed position over the one or more over-pressure apertures, and a low pressure check valve plate disposed on the other side of the control plate and having one or more registering over-pressure apertures provided therein.

2. A normally open valve mechanism including a relatively stationary control plate, the control plate having one or more over-pressure apertures and one or more low pressure relief ports, an over-pressure valve plate disposed on one side of the control plate and covering only the one or more over-pressure apertures while leaving the low pressure relief ports exposed, means biasing the over-pressure valve plate to its closed position over the one or more over-pressure apertures, a low pressure check valve plate disposed on the other side of the control plate and having one or more registering over-pressure apertures provided therein, and a bolt extending through the several plates and having a stop portion to limit the separation of the check valve plate away from the control plate.

3. A normally open valve mechanism including a relatively stationary control plate, the control plate having one or more over-pressure apertures and one or more low pressure relief ports, an over-pressure valve plate disposed on one side of the control plate and covering only the one or more over-pressure apertures while leaving the low pressure relief ports exposed, means biasing the over-pressure valve plate to its closed position over the one or more over-pressure apertures, and a low pressure movable check valve plate disposed on the other side of the control plate and controlling the flow of iluid through the one or more low pressure relief ports provided in the control plate.

ROBERT E. FRIEDRICH. JOSEPH SUCHA.

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

UNITED STATES PATENTS Number Name Date 1,737,705 Collins Dec. 3, 1929 2,419,123 Cumming Apr. 15, 1947 2,420,888 Leeds May 20, 1947

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