Abstract:
A hermetically sealed valve has a magnetically actuated rolling diaphragm valve mechanism, and providing an in-line variable opening valve that is completely sealed and requires no shaft, bushings or moving components through the valve body. This provides a valve with a generally in-line flow, which may be completely isolated from contaminants or from the outside environment. The magnetic actuating mechanism permits precise gradual positional control of the valve and at the same time provides considerably greater actuation force against differential pressure across the valve than has previously been possible. The valve actuation mechanism is readily adaptable to digital control techniques.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an improved flow control valve, which provides a substantially in-line flow direction, and which, in its preferred embodiment, can be inserted within a continuous length of pipe. The valve itself is hermetically sealed and is controllable for variable flow positioning without requiring any shafts or any moving elements to be inserted through the valve wall. All valve seals are therefore stratic pressure seals, and the valve is hermetically sealed, being immersed completely in the fluid but having no chance of leakage or cross contamination from outside influences. 
     The valve comprises an improved rolling diaphragm mechanism especially modified to provide an even-fluid balance and installed so that the flow of liquid through the valve aide the sealing action of the diaphragm. The mechanical configuration is such that, in the closed position, pressure differential forces across the diaphragm resisting opening are completely balanced, thus enhancing the minimum opening forces characteristic of a rolling diaphragm valve mechanism, and permitting higher fluid pressure differentials to be valued that has heretofore been possible with such valving mechandisms. 
     The valve is driven by a novel magnetically driven screw mechanism. 
     The magnetic drive for the screw comprises a multi-pole radial driven element with a matching external multi-pole magnetic drive. This drive mechanism provides considerably stronger magnetic drive forces than the linear magnetic positioning devices currently used in the art, and in addition, provides for increased positional control by permitting arbitrarily small angular positioning of the valve internal drive mechanism. 
     In summary, the valve represents an improved in-line flow control mechanism providing significantly increased actuating force against pressure differential and flow, a significantly increased flow control capability, and a total hermetical seal against outside contamination, all embodied in an in-line mechanism which can be inserted within an existing length of flow pipe. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a cutaway view of the valve as insertedly in-line within a flow pipe, the valve being in a closed position. 
     FIG. 2 shows a cutaway view of the valve as inserted in-line in a flow pipe with the valve in an open position showing the flow of liquid therethrough. 
     FIG. 3 shows a sectional view through the magnetic drive apparatus on a plane orthogonal to the axis of flow through the valve. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, the general outline of the improved valve 2 is shown inserted in-line between an inlet flow pipe 4 and an outlet flow pipe not shown. Threadably affixed to the top of inlet flow pipe 4 is a threaded sealing adaptor 8 having therein an O-ring seal 10 annularly about its upward outer face, and a mating clamping member 12 adapated to a flange 14. Said clamping adaptor 12 threadedly affixes and clamps the lower section 16 of the valve body against the O-ring seal 10 and the threaded adaptor 14 providing an in-line liquid-tight seal. 
     Lower valve body 16 is comprised of a non-magnetic material, such as, for example, bronze. An upper valve body 18, which may either be of the same material as lower valve body 16 or any compatible material, is affixed to lower body 16 by bolts 20. An interface or surface 22 between upper valve body 18 and lower valve body 16 is statically hermetically sealed by a provided O-ring 24 continuously and annularly disposed therebetween around the circumference of the interface surfaces 22. Upper valve body 18 is threadably connected through a second threading adaptor 26 to an upper threaded adaptor 6 which then connects to the outlet pipe (not shown) in the same manner as bottom threaded adaptor 8 and clamping adaptor 12 connects to inlet pipe 4. An O-ring 28 is provided for an upper hermetic seal. 
     A totally in-line valve having a hermetically sealed flow path is contained within lower pipe 4, adaptor 8, lower valve body 16, upper valve body 18, upper adaptor 6, and upper flow pipe (not shown). Within this flow path, symmetrically positioned, is an inner flow control means 30 having a plurality of radially spaced elongated flow orifices 32, circumferentially positioned around control means 30, providing a fluid connection from a lower fluid flow region 34, circumscribed by the inner surface of control means 30 and lower valve body 16, to an upper fluid flow region 36, formed by the inner surface of upper valve body 18 and the outer surface of fluid control means 30. Said outer surface is preferably in a turbulence suppressing smooth shape 38. It is to be noted that said means 30 forms an upper terminator for lower fluid region 34 and a lower terminator for upper fluid region 36. 
     Control means 30 is secured internally to lower valve body 16 by a plurality of securing bolts 40. 
     A cylindrical flexible sealing diaphragm 42, having a lower end and an upper end, is securingly clamped in the annular region formed on the interior of the flow orifice 32 and sealing body 30 by clamping the lower end of the diaphragm between flow adapator 30 and the lower valve body 16 at the radial point 44. Upper end 46 of the diaphragm is clampingly connected to a mid point of an actuating cup 48. 
     Acutating cup 48 positioned axially within lower fluid region 34 by a diaphragm 42, comprises a lower substantially opened orifice frame 50, having at its center point screw drive receiving means 52, and having at its upper end, a substantially vertical support cup surface 54. 
     The screw drive receiving means 52 is mated with a rotatable drive screw 56, which is mounted axially along the center line of the valve body, having an upper pivoting bearing 58 within the flow adaptor 30 providing vertical position support while permitting freedom of rotation and being fixably attached at its lower end 60 to radial magnetic drive means 62. 
     FIG. 3 shows in cross section radial drive magnetic drive means 62 comprising an essentially hollow annular wheel having a rim comprised of multiple alternating magnetic poles, 62A and 62B, for example; the rim is connected to lower end 60 by essentially open connecting means permitting fluid flow, for example spokes 66. 
     On the outside of the non-magnetic lower valve body 16, horizontally aligned with and circumferentially opposing magnetic drive means 62 is a mating multi-pole magnetic driver 64, having a plurality of magnetic poles disposed substantially opposite the magnetic poles, for example 62A, 62B, of inner drive ring 62. 
     Inner drive ring 62 is comprised, in the preferred embodiment, of layered permanent magnetic elements preferably of rare earth ceramic permanent magnets, for example samarium cobalt. The driving multi-pole magnetic means 64 can be comprised either of similar layered permanent magnets in the form of a ring for driving by external mechanical driving means (not shown), or alternately may be an interleaved sequence of electromagnets, which may be switched and driven by any of the standard digital driving means known to the art. In this latter case it is possible to drive the positioning of the inner drive ring 62 by suitable sequencing of the electromagnets through standard digital control means as will be apparent to those skilled in the art. 
     Thus, the inner ring may be rotatably driven either by mechanical drive or by digital electrically controlled drive. 
     In operation, the apparatus as shown in closed position in FIG. 1 and in an open position in FIG. 2 operates substantially as follows. 
     As shown by the flow arrows in FIG. 2, a liquid at a given pressure is provided through inlet pipe 4. Said pressure tends to move the liquid in an upward direction. It is to be understood throughout that directions, such as upward, are descriptive, and that this invention will function in any orientation. In the closed position as shown in FIG. 1, this liquid fills the interior chamber 34 and, passing through the flow passages 50, through the inner surface of actuating cup 54, fills annular space 68. 
     It can also be seen that this liquid pressure is conformably pressing outward diaphragm 42 against flow passage orifices 32. This outward pressure sealingly closes off orifices 32 against any flow by means of the flexible conforming nature of diaphragm 42. The number, size and spacing of flow orifices 32 are adapting by sized to support diaphragm 42 against fluid pressure, in that decreasing the size of each orifice, while increasing the number of orifices supports the diaphragm against increasing pressure, while permitting maximum fluid flow when the valve is open. 
     It is to be noted that as the fluid pressures in chamber 34 and upper annular chamber 68 are substantially equal, the fluid pressure across upper curve 70 is substantially balanced while the valve is in the closed position. Thus, when the valve is in a closed position, hydrostatic forces do not resist an initial downward movement of the diaphragm. 
     To actuate the valve, the magnetic drive field generated by outer magnetic drive 64 is rotated either by mechanical movement of drive ring 64 or by electro mechanical digital sequencing of electromagnetic ring 64. As this field rotates it produces a corresponding annular rotational movement of inner drive means 62. The relatively large plurality of magnetic poles together with a moment arm generated around 0.60 by the outward positioning of the magnetic poles along the distance of spokes 66 produces a considerably enhanced mechanical force over and beyond a single pole linear magnetic actuator. 
     This substantially strong magnetic rotational force rotates screw drive means 56 which acting upon screw drive 52 causes cup 48 to move in a downward direction. Screw drive 52 provides an additional mechanical advantage. Since, as was noted before, the forces about diaphragm 70 are balanced at the initial opening states, this movement initially proceeds essentially only against the resistance induced by hysteresis within diaphragm cylinder 42, which as will be noted, is being rolled inwardly along itself and thus being compressed to a smaller inner diameter downwards than its initial resting closed diameter along the orifice 32. It is for this reason that rolling diaphragm 42 must be made of a deformable, elastomeric material and therefore is a rubberized diaphragm rather than a metallic one. It is important to note, in this regard, that metallic tape or diaphragm mechanisms cannot be used in this application as they are nondeformable. It is also apparant that the stored kinetic energy within the rolling diaphragm differs between the open and closed positions; as a result, the actuation forces and stability of this valve qualitatively differ from the forces encountered in metal tape, displacement diaphragm, or moving shuttle. 
     As shown in FIG. 2, as cup 48 is moved in a downward direction, it pulls the upper terminus 46 of diaphragm 42 downwardly, unrolling diaphragm 42 from across the faces of multiple orifices 32, providing a flow path from flow chamber 34 through orifices 32 and into upper flow chamber 36, whereby the liquid passes into an outlet pipe. It will be noted that as screw 52 is actuated, cup 48 and thus diaphragm 42 may be positioned incrementally along the length of the orifices 32, each of which orifices, being of a substantially oblong nature, provides a variable sized openings, and thereby a variation in the flow rate through the valve. Thus, by means of variable movement of drive means 64, cup 48 may be positioned at any point along threaded drive shaft 56 providing any desired flow, maximum to minimum. 
     It is to be noted that as the valve is opened that a flow is established through flow orifices 32, and that the pressures across diaphragm 42 are no longer in balance. It is for this reason that cup surface 54 is provided to compressibly support the inner downward fold of diaphragm 42. The unbalances portions therefore are restricted solely to the upper curve end 70 of the diaphragm at any point during its actuation. This upper curve 70, because it is created by the bending tensile forces imposed during the inward folding of the diaphragm into an inner smaller cylinder, is relatively pre-stressed against the flow and pressure forces being applied against it. It represents a relatively small area of unsupported diaphragm against which these forces can apply. Thus only a small, relatively strong section of diaphragm remains unsupported against the liquid pressures within the valve; this mechanical combination permits this rolling diaphragm mechanism to work against higher pressures than an unsupported diaphragm. 
     It can also be seen that the drive means requires no mechanical protrusion through the walls of the valve body to outside the point of fluid flow. The valve can be mechanically installed in the in-line position as shown in the preferred embodiment or in any other position which is convenient optimizing flow paths and piping. This valve thus provides considerably enhanced installation flexibility in the design of an overall valving and piping system. 
     It should also be noted that magnetic drive means 62 is composed essentially of an assemblage of ceramic magnets. It is relatively chemically insert, immune to the influences of whatever liquid is being valved, and it avoids any requirement for an internal electromagnetic coil within the fluid path of the valve. No electrical insulation is required, and no electrical power need be introduced into the flow stream.