US2608353A - Electromagnetic valve - Google Patents

Description

Patented Aug. 26, 1952 ELECTROMAGNETIC VALVE Clifton A. Cobb, University City, Mo., assigner to Missouri Automatic Control Corporation, St. Louis, Mo., a corporation of Missouri Application Apri14, 1949, serial No. 85,387 y 2 Claims.

rIhis inventionv relates generally to electromagnetically operated fuel supply valves, and more particularly to the combination with such valves of means for the manual operation thereof in event of power failure and for the automatic restoration to operation by electromagnetic means upon restoration of power.

It is an object of the present invention to provide in an electromagnetically operated valve novel means for manually moving the valve to an open position and for holding it open in event of power failure. l

A further object is to provide novel manual means for opening the valve and means for holding it open, which holding means is manually releasable to permit closing of the valve.

A further object is to provide in an electromagnetically operated valve, manual means for opening the valve and means for holding the valve in an open position when there is no electrical power, which holding means is rendered inoperative upon restoration of power to permit closing of the valve, and in which the operation of the holding means is independent of the operation of the electromagnetic means.

More specically, it is an object to provide in combinati-on with an electromagnetically operated valve, means for manually opening the valve, means normally operative to hold the valve in an open position once it is opened by said manual means when there is no electrical power, and electrically operated means for causing the holding means to be moved to a position to release and permit the closing of said valve upon restoration of power and in which the electrically operated means and the electromagnetic means have independent circuit connections with the source of electrical power.

Further objects and advantages will become apparent upon reference to the following description and accompanying drawings.

In the drawings,

Fig. 1 is the schematic view showing a preferred form of the present invention together with a burner to which the supply of fuel is controlled by the electromagnetic valve, and a diagram of energizing circuits for the valve.

Fig. 2 is an enlarged fragmentary sectional view of the valve shown in Fig. l.

Fig. 3 is a bottom view of the manual actuating mechanism.

Fig. 4 is a sectional view taken on line 4 4 of Fig. 2.

Fig. 5 is a fragmentary view taken on line 5-5 of Fig. 2.

Referring to Fig. 1 of the drawing an electromagnetic valve is generally indicated at l0, having a valve body l l .which has an inlet l2, and an outlet I3 which is connected to a burner i4. The valve body li is further provided with a valve seat l5 adapted to be engaged by a ver` tically reciprocating valve I6. 'The valve I6 has a stem I1 of magnetic material.. Mounted on the body Il is a solenoid comprising a winding I8, and a vcentral sleeve IBa adapted to receive the valve stem I'l whereby upon energization of the winding I8 the valve is lifted vertically by electromagnetic action to an open position and upon de-energization the valve falls by gravity to a closed position.

A circuit for the control and energization of the solenoid winding I8 is provided and includes the secondary winding I9 of a transformer 20, the lead 2l, the thermostatic switch 22 responsive to the temperature of the space heatedV by the burner Ill, a lead 23, the solenoid winding I8,V and a lead 24 back to the other side of the secondary winding i9. A source of power is supplied by the leads 25 and 26 connected to the `primary winding 21 of the transformer 20.

Mountedon the bottom of the valve body `ll and concentric with valve seat l5V is a guide member generally indicated at 28, having` a vertical cylindrical portion 29 and a flange portion 30. Member 28 isattached to the valvebody by means of screws 3l passing through the flange 30 thereof. The member 28 is provided with a vertical bore 32 which receives in sliding fit relationship a manual actuating rod 33. The rod 33 has an upper section 34 adapted to engage the under side of valve I6. The upper-section 3ll is loosely coupled to the lower section 33 by acoupling 35 which permits relative rotation between the sections 33 and 34. `An opening 3,6 in the lower part of the valve body ll is provided and is sealed by a flexible cup shaped diaphragm member 31 having its rim clamped between the iiange 30 of member 28 and the valve body and being attached at its closed end to the lower end of the upper section 34 of the actuating rod thereby to seal the opening 36 and to permit vertical reciprocation of the actuating rods'.

The lower section 33 of the actuating rod is i provided with a notch 38,'and the cylindrical portion 29 of the member 23 `is also provided with a somewhat wider notch 39. Mounted on the cylindrical portion 29 of memberZ in a horizontal position and having one leg attached theretoby means of screws d, is a generally U-shaped bimetal element 4l. The free vleg `42 of the element 4| is adapted to enter the notch 39 in the member 2'9. `The extreme end of the free leg 42 is reduced in width as indicated at 43 in Fig. 5 and is adaptedto engage the notch 38 in Y the lower section 33 of the actuating rod. The

l open at the time power is resumed due to heat the heater ed is provided comprising a lead d5,

the secondary winding i9 of the transformer 2S,

and a lead lit. A casing di is provided which encloses the member 28 and associated parts. The lower end of the actuating rod section 33 extends downwardh7 and exterio'rly' of the casing 7 through an aperture therein and is provided at its lower end with a knurled head et. There is provided a helically wound spring di?, biased between the case :il and the head :i8 which urges the actuating rod downward. The spring a9 also acts as a torsion spring urging the actuatingl rod rotationally in a counterclociiwise directionas' viewed in Fig'. 3 by reason Vof its having one of its endsconnect'ed to the head de at and its lother endconnected to the case All at 5l. ,A stop 52 attached to the case l is provided which Vlimits the rotation of shaft 33 so as to cause the notch 38 therein 'to be aligned with the reduced free end e3 or" the bimetal element fil.

In normal operation when there is a supply of electrical power,V the valve l5 is opened and closed intermittently to supply fuel to the burner id in accordance with the requirements of the space heated thereby. Under these normal conditions the space thermostat controls the op- Veration of the valve.

In the event'there is a failure of electrical power at the source 25-1'6, the valve IG will fall by gravity to a closed position. Under these conditions if it is desired to open the valve manually 'in order to continuek the supply oiheat, the acsubsequently to close the Valve manually, the f knurled head d3 of the actuating rod is rotated clockwise thereby moving the notch 33 out of 'register with the free end i3 of the bimetal element, which permits the spring 33 to move the actuator downward. and permit closing of the valve. Y

When the knurled head [i8 is released after this operation it will automatically be returned rotationally to a position against the stop 52 wherein the notch 38 isagain aligned for registration with the free end of the element il for subsequent resetting in the open position.

If electrical power is resumed when the valve is set in an open position, the heater i4 will be energized independently of energization of the solenoid winding l 8 and will cause the-free leg of element d i to move outward-and release the valve and permit it to close, whereafter normal operation of the valve under control of the space thermostat 22 is resumed. This is an important feature of the invention because it often occurs that the space thermostat 22 which necessarily .must

be included in the solenoid circuit, for the intermittent control of fuel to the burner in accordance with requirements of the space, may be being supplied to the space through manual operation of the valve. It will be seen that if the room thermostat is satisned and in an open position at the time power is resumedand if under these conditions the valve is finan open position Y the thermostat would continue to stay open and the reset mechanism would not be tripped if it were dependent upon energization ofthe solenoid winding as in arrangements of this character now in use.

' The foregoing description and drawing are intended to be illustrative and not limiting the scope of the invention being defined in the appended claims.

I claim:

l. In combination with a normally closed fuel control valve for a space heating system, an electromagnetic actuator for opening said valve,- a source of Velectrical energy, a circuit for said ac-i tuator having connections with Vsaid source of energy and includinga temperature responsive switch responsive to the temperature of a space to beheated, manual means for moving said valve to an open position, temperature responsive detent means having a position at normal amhient temperatures ijor holding said valve open once it is opened, and being responsive to heat to move in a position in which it is inoperative to hold said valve open, and a resistance heater for heating said detent means, said heater having circuit connections with said energy source independent of said temperature responsive switch, and being capable of rendering said detent means inoperative when there is "a supply of electrical energy at said source. y

2. in combination with a normally closed fuel valve for a space heating system, a solenoid 'actuator for opening said valve, a source of electrical energy, a circuit for said actuator having connections with said source of energy and in' oluding a temperature responsive control switch, manual means for moving said valve to an open position, a lai-metal detent having a position at normal ambient temperatures for holding said valve open once it isopened and being responsive to heat to move to a position for releasing said valve, and a resistance heater for heating said detent, said heater. having circuit connections wthsaid energy-source which are independent of said control switch and said-solenoid actuator, whereby said detent is maintained in an'inoperative position at all times when there is a supply of electrical energy at said source.

CLIFTON A. COBB.

REFERENCES CITE) The followingreferences are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 1,603,005 Flair), ,CI'L 12, 1926' 1,844,071 eWel V Feb. 9, 1932 1,924,250 -McGuire Aug. 29, 1933 2,155,358 Cyr 'Apl. 18, 1939 2,187,045 ii/ICCOIl-le Jell. 16, 1940 2,238,401 Shaw Api. 15, 1941 2,358,999 Ray Sept. 26, 1944 2,372,307 Alexander Mar. 27,` 1945 2,487,323 Fewell Nov. 8, 1949 K FOREIGN PATENTS `iumher Country Y Date 249,635 Germany July 26, 1912

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