Mks Instruments, Inc.

Bellofram Corporation

Richard A Benson

John A Denner

Steven M King

Daniel E Smith

David H Alden

A valve assembly including a valve body having an orifice, and a valve member received in the valve body and movable along an axis with respect to the orifice. The valve member includes a cup in an end of the valve member and the cup has an end wall facing the orifice of the valve body. A fulcrum extends from the end wall of the cup towards the orifice, and a plug is received in the cup against the fulcrum and opposite the orifice of the valve body. When the valve member is moved along the axis towards the orifice, the plug contacts the valve body to seal the orifice. The valve assembly also includes a flat spring having an outer portion secured to the end of the valve member and flexible arms retaining the plug in the cup, so that the plug can be articulated about the fulcrum and properly aligned with the valve body to fully seal the orifice when the valve member is moved along the axis towards the orifice.

Valve assembly having articulating rigid seating surface

An improved control and shut off valve assembly is disclosed. The preferred valve assembly provides sufficient forces to overcome biasing forces so as to provide adequate shut off at a leakage rate of less than 10.sup.-9 std cc/sec of He with an atmospheric differential of Helium applied across the valve seat of the assembly, and precise control of the flow rate, all as a function of a single electrical control signal. In accordance with another aspect the valve seat is made from a material softer than the valve seat engagement means so that the seat is coined by the valve seat engagement means when first used so as to insure tight tolerances for sealing the valve passageway during the shut off mode. Finally, in accordance with yet another aspect of the invention, the valve assembly is constructed with no separate parts within the flow path so as to maintain a clean passageway.

Fluid control and shut off valve

An electric coil (20) induces a magnetic flux through a magnetic flow path (22, 24) which terminates in pole faces (26, 28) disposed parallel to a gap (30) therebetween. A non-ferrous pivot element (36) is mounted to one of the pole faces adjacent an edge thereof most distant from the gap. An armature (40) which is at least partially ferromagnetic is held in firm frictional engagement with the pivot element by a taut band (42). The armature pivots about the pivot element in accordance with current flowing through the coil. A fluid nozzle (54) is mounted adjacent the armature such that fluid flow through the nozzle is throttled in accordance with pivotal movement of the armature, hence, the electrical control signal current in the coil.

Current-to-pressure transducer with enhanced performance features

A single fluid-pressure transducer unit, of the type in which sensed electrical capacitance is varied in accordance with electrode deflections induced by pressure changes, is rendered capable of characterizing a wide range of pressures extending from near-vacuum to atmospheric levels, with the aid of a distinctive composite-electrode capsule which interacts uniquely with a conventional type of sheet-metal diaphragm. While sensing relatively low pressures, the exhibited capacitance of the transducer is essentially that appearing between the diaphragm and a nearby electrode carried by the capsule, but, at or near atmospheric pressure, the diaphragm physically engages and deflects that electrode, which is elastically deformable, causing it to vary a further capacitance appearing between that deformable electrode and a companion stationary electrode which is also part of the capsule.

Absolute capacitance manometers

In a current-to-pressure (I/P) transducer which controls output pressures by rapidly and precisely venting pressures of fluid derived from a supply, the movable valve member employed in the venting comprises a mechanically-balanced low-mass armature suspended for restrained pivotal movements by a taut band and incorporating readily-saturated magnetic material disposed in gap-bridging relation to core elements of a stationary electromagnet; the counterbalancing and taut-band suspension of but a small mass renders the armature highly resistant to adverse effects of vibration, and selectable positioning of the venting-valve seat or port to cooperate with one or the other end of the pivoted armature allows for direct or inverse responses to currents fed to the electromagnet.

Current-to-pressure transducers

Sudden increases in fluid pressure which could be injurious to the diaphragm and seals of a sensitive capacitive pressure transducer, or the like, are instantly protectively blocked or 'checked' automatically by a miniature naturally-powered valve having a low-mass one-piece valve member or plug molded of elastomeric material which is shaped and disposed to be immediately propelled into guided tight line-contact seating and sealing as an abrupt pressure surge commences and then to hold such sealing only until the plug is unseated by gravity when either the pressure is rapidly lowered suitably in operation of the transducer or the diaphragm is slowly exposed to increased pressure after enough minute normal valve leakage takes place. A truncated conical valving surface is provided on a mid portion of the movable plug, for line-contacting with the narrow edge of a circular valve-body stationary seat, and tapered and cylindrical guide portions at opposite ends of the mid portion of the plug are trapped within and guided by surrounding inner surfaces of the valve body just upstream and downstream of the seat. Threadedly-united halves of the valve body may be adjustably telescoped to adjust the limits of travel of the valving plug member within them, and, thereby, to adjust or calibrate response characteristics of the valve.

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Bedford, MA, United States of America

Richard A Benson