US2052918A - Motor operated valve - Google Patents

Description

Filed Dec. 15, 1930 ATTORNEY;

, burning unit showing Patented Sept. 1, 1936 PATENT OFFICE 2,052,918 MOTOR OPERATED VALVE Nelson T. Branche,

Toledo, Ohio, assignor,

mesne assignments, to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a

corporation of Delaware Application December 13, 1930, Serial No. 502,120 17 Claims. (Cl. 137-139) This invention relates to improvements in motor-operated valves and more particularly to valve-operating mechanism for valves which are biased toward closed position. Valves of this type have special utility with gas burning apments hereinafter more fully set forth.

Referring to the drawing wherein the preferred embodiment of the invention is shown:

Fig. 1 is a fragmentary side elevation of a gas how the improved valve is associated therewith;

Fig. 2 is a sectional elevation of the valve and operating mechanism therefor, the section being taken on line 2-2 of Fig. 4;

Fig. 3 is an elevation of the valve with a side wall removed, the view being taken on line 3-3 of Fig. 4;

Fig. 4 is a plan view of the valve operating mechanism with the housing removed;

Fig. 5 is a view of a detail of the device, the view being taken on line 55 of Fig. 4;

Fig. 6 is an enlarged detail view of parts shown in Fig. 2, and

Fig. 7 is an electrical diagram showing a simple circuit for connecting the device for operation with a domestic house heating unit.

In the drawing, 10 indicates a box-like conduit forming part of a gas burner and having a secondary air opening normally closed by damper i I. Combustible mixture is supplied to the burners (not shown) by a pipe l2 which leads from a mixing tube l3, gas being delivered to the mixing tube from the gas valve generally indicated at H. Air for mixing with the gas is controlled by an air shutter I 5 at the front of the conduit, said front being closed by a casting l6 having formed therein appropriate passages for delivering the air and gas to the mixing tube. The burner apparatus itself forms no part of the present invention but has been briefly described merely to indicate the environment wherein the invention finds special utility.

The gas valve is either fully open or closed, depending upon heat requirements. When the gas valve is open, the secondary air damper I l is also open and vice versa, appropriate connections being provided between the damper and valve operating mechanism to effect this result. The connection preferably comprises a lever I! one end of which is connected to the damper by a spring I8 and the other end of which is suitably connected to the valve operating mechanism hereinafter described. The lever I! is also utilized for manually opening the valve in case of current failure to the valve opening motor.

The gas valve comprises a valve casing l9 having inlet and outlet connections 20 and 2| and having a dividing partition 22 provided with the passage 23 forming a valve seat. The valve is indicated at 24 and its valve stem at 25, the valve being hinged to the stem as indicated at 26. A spring 27 interposed between the valve and a body 28 at the top of valve casing serves to normally hold the valve secured to the valve casing by a collar 29. Supported by said body 28 is a bowl-like member 30 across the top of which extends a flexible diaphragm 3| through the center of which the valve stem passes in a gas tight manner, the diaphragm providing an effective seal between the valve chamber and the exterior operating mechanism.

The valve-operating mechanism is mounted upon two spaced upright plates 32 and 33 secured to a base plate 34 supported by the member 30. The valve-operating motor is secured to the plate 32 by laterally extending members 35. The motor field is indicated at 36, the poles at 31, the rotor at 38, and the rotor shaft at 39. This shaft projects through the plate 32' and has secured thereto a pinion 40. This pinion drives a gear train which in turn actuates the valve stem 25 by means of a crank and lever arrangement. The final driven gear is indicated at 4|. Secured to this gear is a crank arm 42. The lever i1 previously mentioned is connected with the valve stem 25 by a pin and slot connection 43. Connecting the crank arm 42 and lever I 1 is a link 44 having a lost motion connection 45. The lever is pivotally mounted on a rod 46 which is supported by the side plates 32 and 33.

Delivery of current to the motor will cause its rotor 38 to revolve with resultant opening of the valve 24 as willnow be readily understood. Since the lever I1 is part of the valve-operating mechanism and since this lever is connected to the damper II, it follows that the damper will be operated in unison with the valve 24.

In the ordinary type of motor operated valve, current continues to flow through the motor after the valve has been opened, otherwise the spring 2'! would immediately close the valve, the gear train being such as to permit the spring to rotate the gear train. The present invention, however,

provides means for cutting 01f the current to theto its seat. Said body is removably 15 motor after the valve has been opened and provides a magnetically operated brake for preventing the spring from closing the valve.

Referring to Figs. 3, 4 and 5 wherein the preferred form of braking mechanism is shown, 41 indicates an electro magnet, the core 48 of which is supported by the side plate 32. The armature is an arm 49 hinged at one end as at 50 to an extension from the core 48. The arm 49 is provided at its outer end with a piece of copper plate 49' which acts as a choke or dam in the lines of the magnetic force. Thus fluctuation of the magnetic force due to the pulsations of the alternating current is prevented, as will be readily understood by those skilled in the art, and chattering or vibrating of the arm is prevented. Secured to the arm 49 and projecting laterally therefrom is a spring blade 5|. Secured to the rotor shaft 39 is a brake disk 52. A brake lever is indicated at 53 and its shoe at 54, the lever being pivoted on a suitable support 55 between the plate 32 and the pole leg 31 of the motor. The upper end of the lever is slotted as indicated at 55 and the spring blade 5| extends into the slot. When the armature arm 49 is attracted by the magnet the free end of the blade 5| moves to the right as viewed in Figs. 4 and 5 and applies the brake by actuating the brake lever 53 as will now be understood. The spring blade 5| obviously provides a yielding connection between the armature arm 49 and the brake lever 53. When current to the electro magnet is cut off the brake automatically releases. Since the brake disk 52 is attached to the motor shaft 39, the motor is eflectually kept from rotating and the valve is maintained in its open position when current to the motor is cut off.

As soon, however, as current is shut off from the electro magnet, the valve spring 21 will close the valve, the spring being sufficiently strong to overcome the inertia of the motor and train of gear and drive the valve down with considerable force, thereby insuring a complete seating of the valve. By providing a lost motion connection between the crank 42 and the valve stem as indie cated at 45, rotation of the motor and gear train under the influence of the valve spring is not immediately stopped and consequently not only is there less strain on the mechanism but rebound of the valve incident to reversal of rotation of the gear train and motor following sudden stopping of rotation is effectually prevented. Means for exerting some frictional resistance on the rotating parts may also be provided as by a leaf spring 51 arranged to press on the end of the rotor shaft.

The means for cutting off the current to the valve operating motor and admitting current to the brake operating electro magnet will next be described. Mounted for rotation with the topmost shaft of the gear train is a cam 58 comprising a circular disk having a notch 59 in its periphery. Said shaft rotates approximately 300 during the opening of thevalve. 59 indicates a leaf spring switch-arm the upper end of which always bears on the cam and the lower end of which is secured to a bracket 6!. Also secured to said bracket are two spring switch arms 62 and 63. Arms 60 and 62 are in electrical contact when arm 60 is out of the cam notch 59 and arms 60 and 63 are in electrical contact when arm 50 is in said notch. Wires 60', 62, and 63 lead from the respective switch arms. The arrow on the cam indicates the direction of rotation in opening the valve.

Fig. 7 shows a wiring diagram for the apparatus in connection with a room thermostat. In the diagram, the valve operating motor is indicated at M and the brake-operating electro magnet at E. A room thermostat is indicated at RT and T indicates the source of power which in the present case is a transformer. The equivalent of cam 58 is indicated at C. When the thermostat at RT closes, current will flow to the motor M to open the valve, it being noted that the cam C meanwhile maintains the switch arm 60 at the left to keep the motor circuit closed. The cam rotates in the direction of the arrow adjacent thereto. When the valve has opened the cam will permit the switch arm 69 to move to the right to break the motor circuit and make the electro magnet circuit. When the thermostat opens the electro'magnet is deenergized, whereupon the valve spring will close the valve as will now be readily understood.

In case there should be a failure of current, the

valve may, nevertheless, be manually opened in the following manner and by the following described means. The outer end of the lever I1 is depressed whereupon the valve will open and the crank-carrying gear 4| given a partial rotation. On this gear is a latch pin 64 with which a latch arm 65 may be engaged by pushing on a push rod 66 mounted in a wall of the housing 61 wherein the operating mechanism is contained. A spring blade 68 normally holds the latch arm in retracted position. The pin 64 is so placed on the gear that when it is latched the gear may still be rotated a few degrees in a valve opening direction and consequently when current 35 is again effective at the motor the gear will be rotated sufficiently to automatically release the latch. To put the, matter in another way the pin 64 is so located that the switch arm 60 does not enter the cam notch 59. The spring 69 also serves as a switch arm which when the latch is closed makes contact with a switch blade 69. When this switch is closed the room thermostat is shunted out (see Fig. 7) with the result that even if the room thermostat should be in open position, current will flow to the motor and rotate it sufiiciently to cause release of the latch 65 whereupon the motor circuit is broken and the valve spring will close the valve. In case the room thermostat is closed the motor will continue to operate until the switch arm 60 enters the cam notch 59 and thus transfers the current to the electro magnet which operates the brake.

What I claim is:

1. In a valve operating mechanism the combination of a valve which will automatically close unless positively held open, of a motor adapted to move the valve to open position when power is applied to the motor, holding means adapted when power is applied thereto to prevent reversal of the motor when power thereto is cut off, control means for said motor operable upon actuation thereof to apply power to said motor but not to said holding means. to open said valve, further means operable upon movement thereof in one direction to first cut off power to the motor and then to apply power to the holding means, and means having an operable connection with said valve and movable therewith, said last 7 2. In a valve operating mechanism. the com v rs aosaora bination with a valve which will automatically close unless positively held open, 01' a motor venting reversal of the motor when power thereto 3. In a valve operating mechanism, the combination with a valve which will automatically close unless positively held open, oi. a rotary electric motor adapted to open the valve when power is applied to the motor, of a friction brake adapted to prevent said valve from closing, an electromagnet adapted to actuate said brake, and means power to the motor after it has fully opened the valve and applying power to said electromagnet whereby the brake may be applied for the purpose specified.

4. In a valve operating mechanism, the combination with a valve which will automatically close unless positively held electric motor adapted when brake adapted to prevent said valve from closing, an electromagnet adapted when energized to apply the brake, and means for first cutting off power to said motor and then closing the circuit valve by said motor.

5. In the combination claimed in claim 4, said brake acting on the rotor of said motor.

6. In a valve operating mechanism, the combination with a valve which will automatically close unless positively held open, of a rotary electric motor adapted when energized to open the for supplying power to the electromagnet when power to the motor is cut oil, means connecting said brake and electromagnet comprising a pivoted armature, a spring blade extending from the armature, and a brake lever adapted to be moved by said blade to apply the brake.

7. In a valve operating mechanism, the combination with a valve holding means, means permitting manual opening of the valve in the event power is not available for the motor, means for latching the valve in less than maximum open position following manual opening, a main switch adapted to close the power circuit to the motor, a second switch operable by said latching means to shunt out said main switch and establish the power circuit to the motor whereby when power is again available the motor will be energized irrespective of whether the main switch is closed, the vmotor when energized through the circuit embodying the second switch completing the maximum opening of the valve, and means for automatically releasing said latching means and opening said second switch when the valve is additionally opened by said motor;

8. In a valve operating mechanism, the combination with a valve which will automatically close unless positively held open, said valve having a stem, 01' a rotary electric motor adapted energized to open the connecting said motor and valve stem comprising a crank, a lost motion connection connecting the crank and valve stem, and a gear train connecting the motor and crank.

9. In a valve operating mechanism, the combination with a and operatively connected to said valve stem, the connection between said crank and valve stem including a lever for opening the valve by hand in the event of current failure to the motor, and means operable to latch the valve in open position following manual opening thereof.

valve and meansin combination, a fluid flow controlling element biased to one flow controlling position, a lever, means pivotally mounting the same, means connecting said lever to said fluid flow controlling element at a point'spaced from the pivot point of said lever, a lower operated actuator, a reducconnecting said gear train to said lever at a point spaced from the point at which said fluid flow controlling element is connected to said lever so that upon power being supplied-to said actuator said fluid flow controlling element is moved to a second flow controlling position, said connecting means permitting relative movement between said reduction gearing and said lever, said lever being provided with a portion adapted to be manually operated to permit said fluid flow controlling element to be manually moved to substantially said second flow controlling position upon power failure, and manually operated latching means for maintaining said element in said last named position upon being so moved.

14. A device of the class described, comprising in combination, a valve casing having an inlet and an outlet, a partition wall therebetween having a valve opening therein, a valve adapted to close said valve opening and biased to valve closing position, operating means connected to said valve and movable upon operation thereof in one direction for opening said valve against its bias, the bias of the valve being suflicient to move said operating means during the valve closing operation in the opposite direction at such a speed and through a large enough range that the resulting momentum would be sufiicient to cause the valve to rebound from valve closing position upon reaching the same, and means for preventing such rebounding of the valve due to the momentum thus imparted to the operating means during valve closing movement, said means comprising a friction brake acting on said operating means and effective to retard the movement thereof in valve closing direction.

15. A device of the class described, comprising in combination, a valve casing having an inlet and an outlet, a partition wall therebetween having a valve opening therein, a valve adapted to close said valve opening and biased to valve closing position, operating means connected to said valve and movable upon operation thereof in one direction for opening said valve against its bias, the bias of the valve being sufficient to move said operating means during the valve closing operation in the opposite direction at such a speed and through a large engugh range that the retion gear train connected to said actuator, means upon reaching the same, and means for prevent- I ing such rebounding of the valve due to the momentum thus imparted to the operating means during valve closing movement, said means comprising a lost motion connection between said operating means and said valve and a brake acting on said operating means and effective to retard the movement thereof in valve closing direction.

16. A device of the class described, comprising a valve casing having an inlet and an outlet, a partition wall therebetween having a valve seat formed therein, a valve normally biased against the seat to obstruct fluid flow from the inlet to the outlet, a rotating actuator for the valve, 9. gear train between said actuator and valve whereby the latter may be opened against its bias by the former upon operative energization thereof, the bias of the valve being suflicient to close the valve and rotatethe actuator and gear train in the reverse direction at such a speed and through a large enough range that the resulting momentum built up in the gear train and actuator would be sufficient to cause the valve to rebound from its seat upon striking the same, and means for preventing such rebounding of the valve from its seat due to the momentum thus imparted to the actuator and gear train during valve closing movement, said means comprising a brake effective to retard the movement of said actuator and gear train in valve closing direction.

17. A device of the class described, comprising a valve casing having an inlet and an outlet, a partition wall therebetween having a valve seat formed therein, a valve normally biased against the seat to obstruct fluid flow from the inlet to the outlet, a rotating actuator for the valve, a gear train between said actuator and valve whereby the latter may be opened against its bias by the former upon operative energization thereof, the bias of the valve being sufficient to close the valve and rotatethe actuator and gear train in the reverse direction at such a speed and through a large enough range that the resulting momen-' tum built up in the gear train and actuator would be suflicient to cause the valve to rebound from its seat upon striking the same, and means for preventing such rebounding of the valve from its seat due to the momentum thus imparted to the actuator and gear train during valve closing movement, said means comprising a lost motion connection between said actuator and said valve and a brake effective to retard the movement of said actuator and gear train in valve closing direction.

NELSON T. BRANCHE.

" CERTIFICATE or coaasc'rror.

Eatent No. 2,052,918.

the above numbered patent requ column, line 9, Letters Patent should b September 1, 193! NELSON BRANCHE.

It is hereby certified that error appears in the printed specification of claim 13-, for the word "lower" iring correction as follows: Page 4, first read power; and that the s e read with this correction therein that the same ma;

conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of January, A. D. 1957.

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