US3297044A

US3297044A - Air bleed nozzle

Info

Publication number: US3297044A
Application number: US318973A
Authority: US
Inventors: David H Thorburn
Original assignee: Powers Regulator Co
Current assignee: Powers Regulator Co
Priority date: 1963-10-25
Filing date: 1963-10-25
Publication date: 1967-01-10
Anticipated expiration: 1984-01-10

Description

Jan. 10, 1967 D. H. THORBURN AIR BLEED NOZZLE Filed Oct. 25, 1963 am, @im f 3,297,644? Patented Jan, lli), ld?

3,297,944 AIR BLEED NZZLE David H. Thorburn, Gah Park, lll., assigner to The Powers Regulator Company, Skokie, ill., a corporation of Illinois Filed st. 25, 1963, Ser. No. 3i8,973 6 Claims. (Cl. 137-82) This invention relates to a flapper nozzle arrangement and specifically to an improved dapper nozzle in which the valving characteristic of the ilapper remains essentially the same regardless of its position relative to the nozzle.

Flapper nozzles have been extensively used in pneumatic control systems for regulating variables such as temperature, pressure and the like. The dapper nozzle has many advantages famong which are its simplicity and reliability. One of the problems of the ordinary flapper nozzle arrangement is that when the ilapper moves, the angle of the valving surface presented by the flapper changes with respect to the axis of the nozzle. For example, if the valving surface is at right angles to the axis of the nozzle when the `dapper is in its equilibrium position, then at all other positions of the dapper the angularity will be something other than 90. This change in angularity is a result of the fact that the flapper is generally pivoted at one end or else is 'a cantilever supported at one end.

The change in angularity means that the valving characteristics of the valve surface will be changed so that the relationship between the distance of the dapper from the nozzle 'and the rate of exhaust therefrom is nonlinear. The change in character is particularly undesirable when the force exerted on the flapper by the exhaust from the nozzle is to be utilized as a source of negative feedback indicating that the system has made an appropriate correction of a sensed deviation.

A foremost feature and object of the invention resides in the provision of a dapper nozzle arrangement in which the valving characteristics of the valve remains essentially linear throughout the full range of travel of the fiapper.

A further feature and object of the invention resides in the provision of a flapper nozzle arrangement in which the valving surface supported by the iiapper has essentially the same attitude with respect to the nozzle regardless of the position of the ilapper.

A further feature and object of the invention resides in the provision of a apper nozzle in which the valving surface comprises a spherical member mounted so as to remain essentially concentric with the nozzle throughout the full range of travel of the dapper.

A further feature and object of the invention resides in the provision of a tlapper nozzle arrangement which permits the use of the force exerted on the valve supported by the apper and generated by the exhaust from the nozzle as a source of negative feedback indicating that the system has made a correction of the sensed deviation in the controlled variable.

The aforegoing features and objects of the invention will be apparent upon reading of the speciiication with reference to the following drawings.

In the drawings:

FIGURE l is a sectional view illustrating the improved flapper nozzle in combination with a pneumatic control means for a heating system; and

FIGURE 2 is a cross-sectional view along the lines 2-2 of FIGURE 1.

Referring now to FIGURE l there is shown the subject invention as utilized for controlling a heating system in 'accordance with the temperature of the yambient atmosphere. The heating system itself forms no part of the invention and serves principally to illustrate the same. It will be understood that the heating system is merely by way of example and that the invention may be utilized generally wherever dapper nozzles are used.

The heating system includes a supply pipe 10 through which a source of heat such as hot water ows from a suitable source such as a boiler (not shown) to heat exchanger such as a radiator (not shown). In the supply line l() is a valve 1l which is controlled by means of the motor mechanism l2. The motor mechanism may be of any conventional construction such as `a spring biased diaphragm which is adapted to be forced downwardly against the force of the spring by means of air pressure. As the pressure is increased the diaphragm is forced down so as to close the valve l1. Conversely, as the pressure is decreased the diaphragm is forced upwardly by a spring so as to open the valve. The supply of pressure is transmitted through the conduit 13 which extends from the relay valve i4. The relay 14 may be of the type adapted to generate a pressure signal in response to a pneumatic signal received from the temperature sensing mechanism. The relay 14 is connected to the source of supply pressure by means of the branch conduit i5 which in turn communicates with the conduit 17 leading to a source of supply pressure (not shown).

The supply pressure communicates with the nozzle assembly 28 which substantially continually exhausts air to atmosphere. The exhaust air must pass through the orice assembly 18 including the restrictor plate 24 which is mounted within the fittings 19. The orifice plate includes the orice 25 which is of a relatively small size so as to cause a substantial reduction in pressure as the air passes therethrough. One commonly used orifice size is .006 inch in diameter.

The nozzle assembly 28 comprises an annular member 29 having the exhaust port 3i). The nozzle assembly 28 may be connected in any suitable manner to the restrictor assembly ld, such las by the conduit 32.

A apper valve assembly 34 cooperates with the exhaust port 30 so as to control the rate of exhaust. The flapper valve assembly comprises a lever 35 which is designed to move toward and away from the port 3@ in accordance with variations in temperature. For example as the temperature increases, the lever 35 is adapted to move toward the port 30 and conversely as the temperature decreases, the lever 35 moves away. The lever may be mounted in any suitable manner such as being pivoted at one end as indicated by the numeral`36. The movement of the lever 35 may be effected by any suitable temperature sensitive means such as a Bourdon tube, bellows, or bi-rnetallic element. In fact the lever 35 may be constructed from a temperature sensitive bimetallic element which is fixed at one end and adapted to deflect downwardly toward the nozzle 23 upon sensing an increase in temperature and away from the nozzle on sensing a decrease in temperature,

As the lever 35 moves toward the nozzle 28 the rate of exhaust is decreased. This causes an increase in pressure on the downstream side of the orice plate 24. In fact, if the port 30 were completely shut off the pressure on the downstream side would ultimately equal that on the upstream side. The increase in pressure is transmitted through the conduit 22 to the relay 14. When the pressure increase is of a pre-determined magnitude, the relay i4 will generate a signal of increased pressure which is communicated through the conduit 13 to the motor valve 12. Thus the motor valve will throttle the iiow of hot water through the conduit 1d in an attempt to make a correction for the increase in temperature sensed by the sensing element.

Conversely, if the lever 35 should be moved away from the nozzle 22% the rate of exhaust will be increased. This will cause the pressure on the downstream side of the orice 24 to decrease. The decrease in pressure will be transmitted through the conduit 22 to the relay 14. The relay 14 on sensing a decrease of a pre-determined magnitude will cause a decrease in the pressure sensed by the motor valve 12 so as to further open the valve il in the line l0. This in turn will cause an increase in the ow of hot water so as to correct for the decrease in temperature.

As mentioned previously, one of the problems of the ordinary flapper nozzle arrangement is that when the ilapper moves, the angle of the valving surface with respect to the nozzle changes. For example, it the Valving surface is at right angles to the axis of the nozzle when the flapper is in its equilibrium position, then in all other positions of the flapper the angularity will be something other than 90. This change in angularity is a result of the fact that the apper is pivoted at one end.

The change in angularity means that the valving characteristics of the surface will be changed so that the relationship between the ldistance of the fapper from the nozzle and the rate of exhaust is non-linear. The change in characteristic is particularly undesirable where the force exerted on the llapper by exhaust is to be utilized as a source of negative feedback indicating that the system has made an appropriate correction of a sensed deviation.

The subject invention specifically eliminates the disad- Vantages of the ordinary apper nozzle system and includes a valve member 38 which is adapted to cooperate with the 'port 30 for controlling the rate of exhaust therefrom. In its preferred form the valve 38 is a sphere which is connected by means of the stern 39 to a second sphere 40. The stem 39 extends through an aperture 4l in the lever 35. The sphere 40 rests on the aperture 41 and may be freely rotated about its axes. The only limitation on the rotations of the sphere 40 is the size of the aperture 41 which serves to conne the stern 39.

The sphere 40 is maintained in its seating engagement by means of the spring member 42 which is secured to thelever 35 by means of the rivet 33. The spring mem- -ber 42 -biases the sphere 4@ downwardly into engagement with the aperture 41. The force exerted by the spring member 42 may be controlled by the adjusting screw 43. In the preferred form the force exerted by the spring 42 will be barely enough to maintain the sphere 40 in seating engagement but not to interfere with rotary movement of the same.

As a result of this arrangement the valve member 38 may be freely swivelled in order to maintain an exact alignment with the port 30 regardless of the position of the lever 35. As the free end of the lever 35 moves upwardly the valve member 33 and the stem 39 may be lswivelled in a counterclockwise direction relative to the lever so as to maintain their alignment with the port 30. Conversely, as the lever 35 moves downwardly toward the nozzle 28, the valve 38 and stem 39 will be swivelled in a clockwise direction. In this manner the relationship between the valve member and the port 30 with regard to alignment will be the same throughout the entire range of movement of the lever 35.

The stream of air issuing from the port 30 will serve to center the valve 38 but it may be desirable notwithstanding the natural centering tendency of the air to provide additional means for centering such as the magnet 44. The magnet 44 is positioned within the bore of the nozzle 28. The magnet 44 is arranged with its poles being coaxial with the annular member 29. The magnet 44 is provided with cutaway sides 45 as can be seen in FIG- URE 2 to permit the air to freely pass thereby and out the exhaust port 30. Obviously in this instance the valve member 38 must be constructed of a magnetic material if it is to be acted upon by the magnet 44. The eld of the magnet 44 will center the valve member 38 with respect to its own center.

Thus as the apper 35 moves upwardly the field of the magnet 44 will swivel `the valve member 38 in a counterclockwise direction so as to maintain it in alignment with the port 30. Conversely as the lever 35 moves downwardiy the magnetic eld will move the valve member 33 in a clockwise direction so as to maintain an alignment with the port 3u. Although the valve 38 is rotated relative to the port 3S its natural symmetry eliminates any change in its valving characteristic.

Although certain specic forms and uses of the invention have been disclosed in the description hereinbefore, it is to be understood that this is merely by way of example and is not to be construed as a limitation. It will be apparent to those skilled in the art that certain modiiications may be made within the scope of the claims without departing from the spirit of the invention.

it is claimed:

il. A i'lapper nozzle arrangement comprising a valve member having a stem portion, a spherical valve mounted on one end of said stem and a spherical swivel member on the other end of said stern opposite said spherical valve, a movably mounted valve support member having an opening therein through which said stem portion of the valve extends, a spring biased member in engagement with the spherical lswivel member for maintaining the same in a seated position on said opening, and a valve seat member having a port therein, said valve member cooperating with said valve seat member in coaxial relationship with said port for controlling the ow therethrough.

2. A flapper nozzle arrangement comprising in combination a pivotally mounted apper member having an opening therein, a valve member having a stem portion extending through said opening in said ilapper melmber and having spherical portions at each of its ends, one of said spherical portions acting as a valve and the other of said spherical portions acting as a connection to said tlapper member, a nozzle having a port therein for exhaust to atmosphere, said valve member cooperating with said port for controlling the rate of exhaust, an adjustable spring-biased member for maintaining said other spherical portion in seating engagement on said opening and permitting swivel movement of said valve member and said stem with respect to said apper member, said valve member and said stem being swiveled to maintain concentricity with said port as said apper member moves With respect to said nozzle.

3. A apper nozzle arrangement comprising a valve member having a stem portion, a spherical valve mounted on one end of said stem portion and a spherical swivel member at the other end of said stem opposite said spherical valve, a movably mounted valve support member having an opening therein through which said stem portion extends, a spring biased clip in engagement with said spherical swivel member for maintaining the same in a seated position on said opening, .and a valve seat member having a port therein, said valve member cooperating with said valve seat member in coaxial relationship with said port for controlling the flow therethrough, and magnetic means for swiveling said valve member and said stem as said apper member moves with respect to said nozzle to maintain concentricity of said valve member with said port.

4. A ilapper nozzle arrangement comprising in combination a pivotally mounted apper member having an opening therein, a valve member having a stem portion extending through said opening and having spherical portions at each of its ends, one of said spherical portions acting as a valve and the other of said spherical portions actinfy as a connection to said apper member, a nozzle having a port therein for exhaust to atmosphere, said valve member cooperating with said port for controlling the rate of exhaust, said valve member and said stem being swiveled to maintain concentricity with said port as said llapper member moves with respect to said nozzle, a magnet disposed within said nozzle swiveling said valve unember and said `stem portion as said apper member moves relative to said nozzle to maintain concentricity between said valve member and said port.

5. A apper nozzle arrangement comprising in combination a pivotally mounted apper member having an opening therein, a valve member having a stem portion extending through said opening in said apper member and having spherical portions at each of its ends, one of said spherical portions acting as a valve and the other of said spherical portions acting yas a connection to said flapper member, a nozzle having a port therein for exhaust to atmosphere, said valve member cooperating with said port for controlling the rate of exhaust, said valve member and said stem being swiveled to maintain concentricity with said port as said ilapper member tmoves with respect to said nozzle, a magnet disposed within said nozzle for swiveling said valve member and said stem portion as said apper member moves relative to said nozzle to maintain concentricity between said valve member and said port.

6. A flapper nozzle combination comprising a nozzle connected to a pneumatic system, said nozzle exhausting air from said system whereby the pressure within the system is proportional to the rate of exhaust, a valve member cooperating with said nozzle for controlling the rate of exhaust, said valve member comprising a apper member having an opening therein, a valve member having a stem portion extending through said opening in said ilapper member and having spherical portions .at each of its ends, one spherical portion acting as a valve and the other spherical portion acting as a swivel connection to said apper member, an adjustable spring-biased member for maintaining said other spherical portion in seating engagement on said opening and permitting the swivel movement of said valve member and said stem, and means for swiveling said valve member and said stem Ias said flapper member moves with respect to said nozzle so as to maintain concentricity between said valve member and said nozzle.

References Cited bythe Examiner UNITED STATES PATENTS 1,273,304 7/1918 Yates 251-86 XR 1,832,341 11/1931 Williamson 251-86 2,669,247 2/1954 Olah 137-84 3,237,633 3/1966 Sanville 137--82 ALAN COHAN, Primary Examiner.

Claims

1. A FLAPPER NOZZLE ARRANGEMENT COMPRISING A VALVE MEMBER HAVING A STEM PORTION, A SPHERICAL VALVE MOUNTED ON ONE END OF SAIS STEM AND A SPHERICAL SWIVEL MEMBER ON THE OTHER END OF SAID STEM OPPOSITE SAID SPHERICAL VALVE, A MOVABLY MOUNTED VALVE SUPPORT MEMBER HAVING AN OPENING THEREIN THROUGH WHICH SAID STEM PORTION OF THE VALVE EXTENDS, A SPRING BIASED MEMBER IN ENGAGEMENT WITH THE SPHERICAL SWIVEL MEMBER FOR MAINTAINING THE SAME IN A SEATED POSITION ON SAID OPENING, AND A VALVE SEAT MEMBER HAVING A PORT THEREIN, SAID VALVE MEMBER COOPERATING WITH SAID VALVE SEAT MEMBER IN COAXIAL RELATIONSHIP WITH SAID PORT FOR CONTROLLING THE FLOW THERETHROUGH.