US2257435A - Motor-operated valve - Google Patents

Description

Sept. 30, 1941. Q THUM|M 2,257,435

' MOTOR-OPERATED VALVE Filed Oct. 15, 1940 70 40W PRESSURE 38 5 7.5 TE M.

' Inventor":

Carl Thumim,

1y (5 AMA His Z ctovney.

Patented Sept. 30, 1941 t' U NITE D' STATESPATENT OFFICE. i

Carl Thumim, Yeadonllag assignor to General Electric Company, a corporation of New York Application October 15, 1940, Serial No. 361,295 6 Claims. (01. 137-139) Myinvention relates to a high-pressure motoroperated valve which closes. at very high speed and is particularly adaptable for use in controlling the fluid used with high-voltage circuit breakers of the fluid blast type.

1 In circuit breakers of the fluid-blast type and specifically in air-blast circuit breakers, it is necessary to provide a source of air under pressure for arc-extinguishing purposes. For uniform operation of the circuit breaker, it is desirable that this source of air be maintained at substantially a constant pressure. Where air-blast circuit breakers are to be used out of doors, particularly in a cold climate, it is necessary to remove the moisture therefrom which may be accomplished by compressing the airto a very high pressure of the order of one thousand pounds per reduction of. pressure and holding constant pressure on the low side so that a source of air under substantially constant pressure is available for satisfactory operation of an air-blast circuit breaker. l p

In order to control this pressure reduction, it has been suggested to use electrically operated shut-off valves controlled by a pressure switch. However, a solenoid-operated valve for controlling such high pressures requires a great deal of power to operate and, furthermore, is not sufii- ,ciently fast in its operation since such a valve must close almost instantly upon the pressure being attained in view of the large difference in pressure between the high and low pressure systems. An electric motor-driven valve would be satisfactory from the standpoint of the power required to operate but would be far too slow to maintain a substantially constant pressure on the low-pressure side. vide a valve which would close instantly when the It would be desirable to proproper. pressure is attained on the low-pressure side so as to prevent spilling over of air from the high to the low-pressure side after the proper pressure has been obtained. The opening time of such a valve would not be important but it would be desirable that the valve be so constructed and arranged that, if the proper pressure is attained during the opening of the valve, instant closing thereof will occur even though the full open 'position has not yet been attained.

Accordingly, it is an object of my inventionto provide a new and improved high-pressure valve which will control the flow of fluid between a high and a low-pressure system and maintain substantially constant pressure on the low-pressure system.

It is another object of my invention to provide a motor-operated valve which will close'instantly under certain conditions regardless oiwhether or not the opening operation has been completed.

Further objects and advantages of myinven- 'tion will become apparent as the following description proceeds and the features or novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding off my invention, reference may be had to the accompanying drawing in which Fig. 1 is a perspective view of a motor-operated control valve embodying my invention, Fig.2 is a schematicdiagram showing the valve in the open position, and Fig. 3 is a 'view similar to Fig. 2 showingthevalve at the instant of closing. i 1 7 Referring now to the drawing, I'have illustrated generally a valve M which is connected to a high-pressure system through conduit H and to a low-pressure system through conduit [2. The specific form of valve 1 0 forms no partjof my invention and valve Ill may be any of the types of valves well known to those skilled in the art, such, for example, as a balanced and packed" piston type of valve having a reciprocally arranged valve steml3. j, Y

In order to operate valve I0,'aT-shaped;crank I4 is provided, pivotally mounted in the center to a fixed support I5. One leg of crank 14 is operatively connected to valve stem l3 at I6 while'the second leg is operatively connected throughpin I! and rollers l8 to compression springs 19 which tend to rotate T-shaped crank 14 in the counterclockwise. direction to .close valve Ill. The third or middle leg of T-shaped crank I4 is operatively connected at 20 to a collapsible thrust transmitting linkage and more specificallyto link 2| of a toggle generally indicated at 22. The other link 23 oi toggle 22 isconnected at 24 with an eX- tension 25' of crank or pivotally mounted member 2 5. Pivotally mounted member 25 is suitably supported at either end. 25 thereof on fixed supports, not shown, and is normally biasedin a clockwise direction by spring means 26.

Pivotally mounted memberor crank 25 is provided with an arm 21 for supportingfan armature 28 which is adapted to close the magnetic and 2, valve Ill is held in its open position against v the bias of springs l9. center travel of toggle 22, a suitable extension 3| is provided on link 2| which engages a stop 32 on link 23, thus providing a suitable locking means. A suitable spring means 33 is provided normally to bias toggle 22 to the undercenter position. Whenever electromagnetic means or solenoid 29 is deenergized, armature 28 is released and pivotally mounted member or crank 25 is free to rotate on pins 25". Assoon as this occurs, spring means I9 cause a counterclockwise rotation of'T-shaped crank l4 and, consequently, closing of valve Ill. Furthermore, toggle 22 is no longer held in the overcenter position by'the force ofsprings l9. and, consequently, spring 33 causes the toggle to assume the undercenter position shown in-Fig. 3.

In order to open solenoid-operated valve I9,

I provide a suitable electric motor 34, which is preferably connected through suitable reduction gearing and shaft 35 to crank 36 keyed to the end of shaft 35. Crank 36 is provided with a roller 31 which is arranged to engage with an extension 23 of toggle link 23 so that rotation of crank 36 will force toggle 22 to the overcenter position after which it snaps further over center by the action of springs 19 until it strikes the self-contained stop embodying members 3| and 32, Whenever valvel 0 is closed, spring means 26 tends to move pivotally mounted member 25 so that armature 28 is in a position to be held by electromagnetic means or solenoid 29 when the latter is energized.

Inorder to control the operation of solenoid 29 and electric motor 34, I have provided a suitable control circuit by means of which solenoid 29 and electric motor 34 are connected in parallel to a suitable source of power 38 through a pressure switch 39 which is connected in the lowpressure circuit. Whenever the pressure in the low-pressure system falls below a predetermined value, pressure switch'39 is closed, as shown in Figs. 1 and 2, to energize solenoid 29 and motor 34. As soon as the proper pressure has been attained in the low-pressure system, pressure switch 39 opens deenergizing the solenoid and motor 34.

The operation of the arrangement disclosed in Figs. 1 to 3 will be understood by those skilled in the art in view of the detailed description included above. Referring now to Figs. 1 and 2, with the valve in the open position by virtue of the overcenter position of toggle 22, it will be observed that the disposition of the valve will be maintained as long as pressure switch 39 remains closed. As soon as the predetermined pressure has been attained, pressure switch 39 opens, as shown in Fig. 3, to deenergize electromagnetic means or solenoid 29 and motor 34, whereupon pivotally mounted member 25 rotates in a counterclockwise direction to allow valve [0 to close even though toggle 22 is still in the over- In order to limit the overcenter position. Spring 33 causes the toggle to assume the undercenter position as soon as spring means l9 are released. Similarly, spring means 26 causes pivotally mounted member 25 to assume the position shown in Figs. 1 and 2 as It will be observed that high-speed closing of V valve I!) may occur at any time regardless of whether or not the opening operation of the valve has been completed. Furthermore, motor 34 and crank 35 may continue to rotate after the valve has been fully opened inview of the fact that valve 19 is generally open for a relatively short time, consequently, motor 24 will be deenergized when solenoid 29 is deenergized. If it should be desirable to keep valve l9 open for a longer period of time, it will be obvious to those skilled in the art that a suitable cut-off switch for motor 34 could be providedas soon as toggle 22 reached its overcenter position; for example, a suitable cut-off switch could be associated with the extension 23' of toggle link 23.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention and I, therefore, aim in the appended claims to cover all such changes and modifications.

What I claim as new and desire to secure Letters Patentof the United States is 1. In combination, a valve having an operating stem, spring means associated with said stem for urging said valve to the closed position, a

pivotally mounted member, a toggle having one end thereof connected to said member, the other end of said toggle being operatively connected with said valve stem, electromagnetic means for holding said pivotally mounted member in fixed relationship so that said Valve may be opened against the force of said Spring means when said toggle is moved to its overcenter position, and means for deenergizing said electromagnetic means to release said pivotally mounted member so that closing of said valve independently of said toggle is obtained.

2. In combination with a valve for controlling the flow of fluid, spring means operatively connected with said valve to bias said valve to the closed position, a pivotally mounted member, an electromagnetic latch for holding said pivotally mounted member stationary when said electromagnetic latch is energized. a toggle operatively connected between said pivotally mounted member and said valve, motor-operated means for opening said valve by exerting a force on said toggle to move said toggle to the overcenter position against the force of said spring means, and means for closing said valve regardless of the position of said toggle and independently thereof upon deenergization of said electromagnetic latch and consequent release of said pivotally said operating stem, locking means for maintaining said valve in the open position against the force of said spring means, and latching means associated with said collapsible thrust-transmitting structure and arranged upon release to cause collapse of said thrust-transmitting structure and permit closing of said valve independently of said locking means or said means for urging the valve to the closed position.

4. In combination, a valve having an operating stem, spring means associated with said stem for urging said valve to the closed position, means for producing opening movement of said valve, a collapsible thrust-transmitting structure interposed between said last-mentined means and said operating stem, locking means for maintaining said valve in the open position against the force of said spring means, and magnetic latching means associated with said collapsible thrust-transmitting structure and arranged upon release to cause collapse of said thrust-transmitting structure and permit closing of said valve independently of said locking means or said means for urging the valve to the closed position.

5. In combination, a valve having an operating stem, a spring associated with said stem for urging said valve to the closed position, means for producing opening movement of said valve against the force of said spring, a collapsible thrust-transmitting linkage interposed between said last-mentioned means and said operating stem, and means for rendering said collapsible thrust-transmitting linkage effective or inefiective with respect to transmitting th force from said first mentioned means to said valve stem, said means for rendering said thrust-transmitting linkage eifective or ineffective being so constructed and arrangned as to permit closing of said valve independently of said firstmentioned means.

6. In combination with a valve for controlling the flow of fluid, a spring operatively connected with said valve to bias said valve to the closed position, a motor for producing opening movement of said valve against the force of said spring, a collapsible thrust-transmitting linkage interposed between said motor and said valve, and magnetic means for rendering said collapsible thrust-transmitting linkage effective to transmit force from said motor to cause opening of said valve, and means for causing said magnetic means to render said collapsible thrusttransmitting linkage ineffective so that closing of said valve at high speed may occur independently of the position of said motor or of said collapsible thrust-transmitting structure.

CARL THUMIIVL

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