US2665713A - Control valve - Google Patents

Description

Jan. 12, 1954v R. R. cRooKsToN HAL 2,665,713

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.IW Nm, slm n. Nw nu E N l n@ am N. E E a Q 2% S m O .mU`II` Patented Jan. l2, i954 UNITED STATES PATENT OFFICE CONTROL VALVE Robert R. Crookston and ArthurV L. Seljos, Houston, Tex., assignors, by mesne assignments, to Standard Oil Development Company, Elizabeth, N. J .,.a corporation of Delaware Application January 9, 1952, Serial No. '265,557

(Cl. IS7-689) 3 Claims.

This application is directed to a control valve assembly.

More specifically, this application is directed to an assembly having a housing in which are two movable cooperating valve elements which control the flow of fluid through a passage in the housing, one of the elements being mounted on a valve stem for adjustment to a selected position and the other valve element Vbeing operatively connected to a fluid motor for movement from an initial position either to a position to reduce or a position to increase the flow area through said passage.

Other advantages of the present invention will be seen from the following description taken with the drawing in which:

Fig. 1 is a view partly in section showing an embodiment of the present invention;

Fig. 2 is a fragmentary view partly in section showing the remainder of the device of Fig. 1; and

Fig. 3 is a view partly in section, showing an other embodiment of the present invention.

In the drawing principal parts or assemblies making up the invention are designated by letters and other parts are designated by reference numerals. Like parts in the two embodiments of Figs. 1 and 2 are designated by like characters.

Turning now specifically to the drawing and f C. An adjustable stop assembly G is carried by assemblies E and F.

Housing part A has a fluid inlet and a fluid outlet |2 with a longitudinally extending central passage I3. Passage I3 is connected to inlet II through passage |4 and to outlet I2 by passage I5. i

Member I6 of assembly E has its left end within the central passage I3 of housing part A. While member IB is a single member, it may be considered both a valve stem and a valve surface or valve seat. .The left end of member I6 is provided with ports I8 and a central passage having a wall I9, which wall terminates in a seat which is adapted to cooperate with another valve member oi assembly F which will be hereafter described. The member I5 is connected to housing member A by means of screw threads 2| which allow seat 20 to be adjusted longitudinally by rotation of member I6. The right portion of member I6 may be considered the valve stem portion and where it passes out of housing part A the space between housing part A and member I 6 is sealed by a suitable packing means shown as packing 22, ypacking gland 23, and compression nut 24. A hand wheel is secured to the extreme right end of member I6. A gear 26 is also mounted on the valve stem part of member I 6 outside housing part A. Gear 26 is adapted to mesh with another gear (not shown) for rotating member I6.

The combined valve and fluid motor assembly F consists of an elongated member 30 which provides a valve surface and also is the central portion of a piston. Mounted on the left portion of member 30 are ring-shaped members 3| and 32 which are separated by a sleeve 33. Member 30 has a projecting shoulder 34 against which ring member 3| abuts, and the extreme left end of member 30 is provided with screw threads mating with corresponding screw threads of a nut 35 whereby the parts 30, 3|, 32, 33, and 35 are fixed together to form a piston unit.

Members B and C form a hollow cylinder with their inner surfaces 36 and 3l upon which surface members 3| and 32 slide longitudinally. The inner surfaces of members 3| and 32 are provided with 0-rings 39 to form a tight seal between members 3| and 32 and members 30 to prevent the leakage of fluid at these points. The outer portions of members 3| and 32 are provided with O-rings 4I for sealing the space between the piston and the cylinder walls previously mentioned.

The piston made up of members 30, 3| 32, and 34 is biased to `a central position by spring Y42 which is mounted around the sleeve 33. The wall of housing member C is cut away so as to form a shoulder 43 and also to expose a portion of the left end of housing' member B to form a similar shoulder 44. A cage member is arranged with one end abutting against shoulder 44 and the other end constraining the right end of spring 42. A corresponding cage member 4B at its end has a shoulder abutting against the shoulder 43 of housing member C and a shoulder constraining the left end of spring 42. The arrangement of the cage members andthe spring stabilizes the piston assembly F to a central position but allows movement of the assembly either to the right or to the left under forces'which overcome restraining force of this spring.

Between the right end of member 3l of assembly F and housing part D is a space 5U to which access is provided by port 5l in housing part B. Between the left end of member 32 of assembly F and housing part D is a space 52 to which access is provided by port 53. It will be obvious that if pressure (such as compressed air pressure) in space 52 is greater than the pressure in space 50 the piston will be driven to the right against the restraining force of spring 42 whereas if the pressure in space 52 is less than the pressure in space 50 the piston will be driven to the left against the restraining force of the spring.

The right hand portion of part'35 of assembly F projecting beyond the piston is designated as 54. Part 5s may be considered to be a valve stem and passes through a corresponding central passage in housing part B with the space around it sealed by an O-ring 55. The right end of part 5ft carries valve surfaces consisting of a shoulder or seat 56 which joins Va generally parabolic surface of smaller diameter 5l. Valve seat 5t and parabolic valve surface 51 of assembly F are arranged to cooperate with corresponding surfaces I9 and Ztl of assembly E. That is to say, parabolic surface El of assembly F in cooperation with surface 2Q of assembly E acts as a throttling or flow restraining orifice whereas contact of shoulder or seat 55 of assembly F with seat 2s of assembly E completely stops the ow of iluid through passage I3 of housing member A. Y

Thus, since the extreme right hand portion of member 3@ of assembly F acts as a valve portion, movement of assembly F either to the right or to the left drives its valve surfaces 55, 5l either closer to or away from the corresponding valve surfaces i9; 2li of member E. If the pressure exerted by compressed air in space 52 is greater than the pressure in space 50, assembly F will be driven to the right and will bring its valve surfaces 55, 5l' closer to the surfaces i9, 2B of assembly E; whereas, if the pressure in space 52 is less, than the pressure in space 5D, assembly F will be moved to the left to move valve surfaces 5S, 5l further away from the valve surfaces I9, 2o of assembly E.

Y The maximum distance the assembly F may move to the left may be controlled by stop assembly G. The purpose of this assembly is to provide a limit for the maximum distance the valve surfaces of assembly G may be separated from the valve surfaces of assembly F. Stop assembly G consists of a cylinder 59 which is secured to the wall 6@ of the central cavity in the left hand portion of part t of assembly F by means of screw threads Projecting Within the cavity of member 3S is a rod portion 62 of housing portion D, the right end of rod 62 having an annular groove in which is arranged an O-ring 64 which is in contact with wall 60 to prevent leakage between the surfaces at this point. In order to allow adjustment of cylindrical part 59 it has attached to it a rod 65 which extends to the right through a central passage in member 3@ and thence through a central passage in member i6 and passes out through the right end of member I6. Where rod B5 passes out of member i6 it is sealed by means of an O-ring 65 and follower El. Hand wheel 25 has a central opening which allows a control knob t8 to be mounted on the right end of rod (i5 whereby the cylindrical member 59 of assembly G may be moved independently of the movement of member I8 by means of hand wheel 25 or gear 26.

A second embodiment is shown in Fig. 3. This embodiment differs from that of Figs. 1 and 2 inthe arrangement of the stop means used to limit the movement of assembly F to the left. In this embodiment parts identicalwith those of Figs. 1 and 2 are given corresponding reference characters and the parts which serve the same purpose but are of different construction are designated by being primed. In the embodiment of Fig. 3 the stop assembly G' consists of a threaded rod 10 which is mounted on housing member D. The left end of rod 10 terminates in a control knob 68. Where rod 'I0 passes through member D', the opening is sealed by packing gland ll. In the embodiment of Fig. 3 the 'inner member 3B of assembly F has a central passage with a right end terminating in a wall l2. It will be seen that the right end of rod l0 upon contact with wall 120i member 39 limits the extreme left movement of assembly F. It will be noted that the only other part of the embodiment of Fig. 3 which differs from Figs. 1 and 2 is part IIB which lacks the central passage which is necessary in part It in the embodiment of Figs. 1 and 2, in order to accommodate rod 65. It will be seen that in both of the embodiments shown, the assembly E may be adjusted either by a hand wheel or through gears to a desired position which allows the position of valve surfaces is, 2S to be adjusted quite accurately. The assembly F is biased to a central positioni at which position the valve surfaces 56, 51 are also accurately fixed, but the assembly F is provided with a fluid motor which allows rapid movement from this initial position either to the right to reduce the flow'area from the initial position or to the left to increase the llow area from the initial position, the stop assembly G of Figs. 1 and 2 and the stop assembly G of Fig. 3 being adjusted so that the maximum area of flow can be limited by the operator.

What we desire to claim as our invention is:

l. Avalve control mechanism comprising, in combination, a housing having a central uid passage extending longitudinally through a portion of said housing with a first end communicating with an inlet port and a second end communicating `with an outlet port, the housing having a hollow cylinder portion separable from and coaxial with said central passage with a first inlet at a rst end and a second inlet at the second end of said hollow cylinder, a rst member having a first end extending outside said housing through a packed opening and a second end extending into the central fluid passage and terminating in an annular valve seat surrounding a central bore in said member, the central passage connecting said inlet port with said Vbore through radial ports opening from said bore, a

sealing member mounted on the second end of said member at a point between said valve seat and said ports and making a fluid-tight seal with the walls of said central passage, said first member being adjustably secured to said housing by screw threads for longitudinal movement of the valve seat in said central passage, a dumbbell-shaped piston assembly arranged for slidable movement longitudinally in the hollow cylinder portion of the housing and sealed from said central passage, a rst end of the piston assembly including an axially projecting second member with a projecting end having an annular valve seat surface and a smaller diameter parabolicshaped valve surface in the central fluid passage coaxial with and facing the annular valve sea-t of the first member, the second member being adapted to be moved in a rst direction to cause the parabolic surface to enter the central bore of the rst member until its valve seat seals with the valve seat of the first member, a spring arranged around the smaller central portion of the dumbbell-shaped piston, a first cage member in contact with a iirst end of the spring and said cylinder portion to prevent movement of the first end of the spring in the first direction and a second cage member in contact with a second end of the spring and the cylinder portion to prevent movement of the second end of the spring in the opposite direction.

2. A device in accordance with claim l in which a portion of the piston assembly and a portion of the housing assembly have stop surfaces which cooperate to limit the movement of the piston in the opposite direction.

3. A valve control mechanism comprising, in combination, a housing having a central fluid passage extending longitudinally through a portion of said housing with a first end communicating with an inlet port and a second end communicating with an outlet port,fthe housing having a hollow cylinder portion separable from and co-axial with said central passage with a first inlet at a first end and a second inlet at the second end of said hollow cylinder, a first member having a first end extending outside said housing through a packed opening and a second end extending into the central fluid passage and terminating in an annular valve seat surrounding a 3 central bore in said member, the central passage connecting said inlet with said bore through ra- 6 dial ports opening from said bore, a sealing member mounted on the second end of said member at a point between said valve seat and said ports and making a fluid-tight seal with the Walls of said central passage, said first member being adjustably secured to said housing by screw threads for longitudinal movement of the valve seat in said central passage, a piston assembly arranged for slidable movement longitudinally in the hollow cylinder portion in the housing and sealed from said central passage, a first end of the piston assembly including an axially projecting second member with a projecting end having a rst annular valve seat surface and a second smaller diameter valve surface in the central iluid passage coaxial With and facing the annular valve seat of the rst member, the second member being adapted to be moved in a rst direction to cause the second valve surface to enter the central bore of the first member until the first annular valve seat surface seals with the valve seat of the first member, and centering means mounted in said housing cooperating with said piston to bias it in a position with a second valve surface of the second member outside the central bore of the rst member.

ROBERT R. CROOKSTON. ARTHUR L. SELJOS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 640,615 Borden Jan. 2, 1900 1,709,119 Cunningham Apr. 16, 1929 2,090,301 Makins Aug. 17, 1937 2,398,870 Thornhill Apr. 23, 1946

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